阅读说明：本技术 预制桩和预制柱连接承台施工方法 (Construction method for connecting precast pile and precast column with bearing platform ) 是由 徐磊 付书生 沈维成 彭申凯 刘晓晗 刘向前 崔健 危明 于 2021-09-22 设计创作，主要内容包括：本发明提供预制桩和预制柱连接承台施工方法,涉及建筑施工技术领域,包括以下步骤：预制管桩制备→承台基坑开挖→预制管桩填芯混凝土施工→承台及杯口钢筋绑扎→承台及杯口模板安装→承台及杯口定位块混凝土浇筑→承台基坑回填→承台杯口清理及C50环氧砂浆调平层施工→预制墩柱安装→承台杯口后浇混凝土施工,本发明步骤S8中,将环氧砂浆涂抹到刷好基液的基面上,此种设计,环氧砂浆调平层可提高墩柱底端的密封性,同时提升墩柱定位垂直度,防止因杯口不平或墩柱底端不平导致的安装垂直度不符合要求,提高墩柱的定位垂直度,能够方便对墩柱的垂直定位点进行找寻,以便于进行施工,进而提升施工效率。(The invention provides a construction method for connecting a precast pile and a precast column with a bearing platform, which relates to the technical field of building construction and comprises the following steps: the method comprises the following steps of S8, coating epoxy mortar on a base surface brushed with base liquid, wherein the epoxy mortar leveling layer can improve the sealing property of the bottom end of the pier column and improve the positioning perpendicularity of the pier column, so that the mounting perpendicularity caused by the fact that the cup mouth is uneven or the bottom end of the pier column is prevented from meeting the requirement, the positioning perpendicularity of the pier column is improved, the vertical positioning point of the pier column can be conveniently found, construction is facilitated, and further the construction efficiency is improved.)

1. The construction method of the precast pile and the precast column connecting bearing platform is characterized by comprising the following steps of:

s1, preparing a prefabricated tubular pile, which specifically comprises the following steps: after the pile top meets the requirement of design elevation, the connection of the tubular pile and the bearing platform can be constructed according to a design drawing, before pouring core filling C50 micro-expansion concrete, the inner wall of the tubular pile is cleaned up by floating slurry, measures such as coating cement paste on the inner wall, concrete interface agent or micro-expansion concrete are adopted to improve the integrity of the core filling concrete and the concrete of the pile body of the tubular pile, a supporting plate is arranged and a framework is placed, a main rib connected in the pile is firmly welded with a tubular pile end connecting plate, and a welding seam meets the requirement of design specification;

s2, excavating a foundation pit of the bearing platform, and pouring a cushion layer, wherein the method specifically comprises the following steps: excavating a foundation pit to a designed elevation, performing circular cutting on a pile head by using a concrete cutting machine, cutting the pile head to the designed elevation, cleaning and trimming a pile body reinforcing steel bar extending into a bearing platform into a designed shape, re-measuring the elevation of the pile top, performing pile foundation detection, entering the next procedure after the pile body reinforcing steel bar is qualified, manually leveling after mechanical excavation is completed, pouring a concrete cushion layer according to the requirement of a design drawing to be used as a bottom mould of a structure, wherein the top surface of the concrete cushion layer is not higher than the elevation of a base, and the edge of the concrete cushion layer extends out of the edge of the bearing platform by 20 cm;

s3, precast tubular pile core filling concrete construction: in order to ensure the integrity and structural stress of the bearing platform and the prefabricated pipe pile, core filling reinforced concrete construction is carried out on the prefabricated pipe pile top by 4m, and the pipe pile is cleaned → the steel bar and the supporting plate are processed → the mould is hung and installed → the core filling concrete is poured;

s4, binding of a bearing platform and a cup opening reinforcing steel bar: the semi-finished products of the reinforcing steel bars are processed in a centralized way in a reinforcing steel bar processing factory, and the processed semi-finished products are transported to a construction site by a transport vehicle for installation;

s5, installing a bearing platform and a cup opening template: processing and installing a template after finishing processing and installing bearing platform steel bars and reporting and testing, wherein the bearing platform adopts a shaped steel mould or a wood mould with the thickness not less than 18mm, four angular points and axes at the positions of the bearing platform and a central positioning block are measured and discharged during template installation, the template is erected according to a control point, the erection of the template is accurate, particularly the geometric dimension and the axis position of the template, the template is firmly fixed, a specially-assigned person is required to inspect the template during concrete pouring, the position of the template is ensured not to deform, the template is not run, slurry is not leaked and misplaced, in addition, color-painting oil is required to be brushed before the template is erected, the engineering quality reaches the internal beauty and the external beauty, after the template installation is qualified according to the requirements, sundries in the template are cleaned, a supervision engineer is informed to check and accept, and the preparation work for pouring concrete is carried out;

s6, pouring concrete on the bearing platform and the cup rim positioning block: the working performance of concrete is strictly controlled in the pouring process, the concrete is prevented from separating, the concrete is continuously poured in a layered mode, the layered vibration is carried out, the one-step forming is carried out, the concentrated material piling is strictly forbidden, the side pressure of a local template of a substrate is prevented from being large, the concrete is prevented from obviously layering in appearance, the layering interval pouring time does not exceed the initial setting time of the concrete determined by a test, an insertion type vibrator is adopted for vibrating and compacting all the concrete (particularly gaps between reinforcing steel bars and the template and dense positions of the reinforcing steel bars), a vibrating rod is kept at a distance of 5-10 cm from a side mold, a lower layer concrete is inserted into the vibrating rod for 5-10 cm, the continuity between the upper layer concrete and the lower layer concrete is kept, insertion points are uniform during vibration, the vibrating rod advances in a line or in a staggered mode, the moving distance is not more than 1.5 times of the acting radius of the vibrating rod so as to avoid over-vibration or leakage-vibration, the vibrating rod is pulled out while vibrating after each vibration, the vibrating rod is not inclined or transverse, strictly forbidding to stop vibrating, pulling out the rod to avoid causing the concrete to have a cavity, taking the concrete as the concrete is not sunk any more and no bubble emerges, and paying attention to not touch and loosen the template or shift the reinforcing steel bar during vibrating, wherein in the process, a laboratory needs to detect the workability of the concrete at any time, pour the concrete when the workability meets the requirements, leave and take test pieces according to the specifications, and put a group of test pieces and a bearing platform to be cured at the same time under the same curing condition;

s7, backfilling a foundation pit of the bearing platform: when the bearing platform reaches the life-preserving period, the bearing platform is required to be refilled in time, symmetrical layered refilling and compaction are carried out during refilling, foundation pit refilling is carried out twice, the construction of the upright column is not influenced by the first refilling, all the bearing platform is refilled after the construction of the pier column is finished, the refilling ground is slightly higher than the original ground at the periphery, the problem that the pit is accumulated with water is avoided, the bearing platform is soaked, and the two sides are symmetrically carried out during refilling, so that the structure is prevented from being damaged by bias voltage or the stability and the use function of the structure are influenced;

s8, cleaning a cup opening of a bearing platform and constructing a C50 epoxy mortar leveling layer: before the prefabricated pier is installed, an axial cross line is arranged on the top surface of a poured bearing platform in a bouncing mode and serves as a reference line for pier column installation, and meanwhile whether the position of a positioning block and the elevation of the bottom of a cup opening are within a required range or not is checked;

s9, mounting the prefabricated pier stud:

s9.1) hoisting the prefabricated pier and then placing the prefabricated pier on geotextile to avoid secondary pollution caused by ground contact;

then cleaning the pier body, wherein a watering cart is used for cleaning, firstly, preliminarily cleaning the pier body, then cleaning the pier body by using a brush, and wiping the pier body by using a rag after cleaning;

s9.2) hoisting the prefabricated pier needs to select hoisting machinery meeting the site construction requirements for hoisting operation, the hoisting operation is directed by a special person, and an interphone is used for directing a truck crane driver, site operators and operators for adjusting the verticality, so that the hoisting safety is ensured;

s9.3) checking the installation verticality of the pier stud: the verticality of the prefabricated pier can be controlled by a vertical angle, namely the verticality of the prefabricated pier is adjusted by theodolites in two directions (forming a 90-degree angle with each other), and the prefabricated pier is frequently leveled in the measurement process to keep vertical;

s9.4) arranging 4 guy cables on each pier column, wherein an included angle between each guy cable and the ground is 45 degrees, and controlling the verticality of the pier columns and the stability of the pier columns before concrete pouring by adjusting the guy cables;

s10, post-pouring concrete construction of the cup mouth of the bearing platform: after the pier stud is installed, after the pier stud is inspected to be qualified, pouring concrete in the cup mouth, wherein the designed strength of the concrete in the cup mouth is C40, pouring the concrete by adopting a sliding chute is slowly placed in the cup mouth, the periphery of the concrete is symmetrically and uniformly poured, the concrete is vibrated in a layered mode until the top of a pouring cushion cap is flush, and the cup mouth concrete covering cotton quilt constructed in winter is maintained.

2. A precast pile as recited in claim 1, wherein: the precast pile comprises precast tubular pile, steel sheet hanging die, precast pier, pier stud and guy rope.

3. The precast column connection deck construction method according to claim 1, wherein: the specific construction steps in the step S3 are as follows:

a) the floating slurry on the inner wall of the precast tubular pile is cleaned and has no mud, sand and accumulated water;

b) the connection of the pile tops of the pile splicing and pile cutting and the bearing platform meets the design specification and the drawing requirements;

c) cleaning the pile core, and if accumulated water exists in the pile core, reducing the pile core to below 4m of the pile top;

d) the processed steel plate hanging die is placed into the tubular pile to control the size of the inserted pile and is fixed by a cross-shaped reinforcing steel bar frame;

e) and after the hanging die is installed, pouring core concrete, wherein the concrete is required to be vibrated tightly but not excessively vibrated when the concrete is poured.

4. The precast column connection deck construction method according to claim 1, wherein: the specific construction steps in the step S4 are as follows:

A) before the bearing platform is blanked, the steel bar must be straightened, the blanking size must be strictly checked by construction technicians and executed, the steel bar is uniformly manufactured in a steel bar processing factory and bent into a semi-finished product by using mechanical processing, the bending angle and the length of the straight part are ensured,

after the processing is finished, the processed products are orderly stacked according to the classification of the specification and the variety, and replacement workers cannot be mistakenly taken and misplaced when taking the products, so that the accuracy of the formed framework is ensured;

B) the steel bar framework binding method is preferably a cross-shaped buckle binding method, a forward buckle is not required to be adopted, the steel bar deformation is prevented, and core filling reinforced concrete construction is carried out on the prefabricated pipe pile top 4m in order to ensure the integrity and structural stress of the bearing platform and the prefabricated pipe pile.

5. The precast column connection deck construction method according to claim 1, wherein: the specific construction steps in the step S8 are as follows:

q1) chiseling the concrete at the bottom of the cup mouth, and cleaning loose particles and dust after chiseling;

q2) after the epoxy mortar base liquid is mixed, uniformly coating the base liquid on the bottom of the cup mouth by using a brush, wherein the base liquid is required to be brushed as thin and uniform as possible without flowing or leaking;

the base liquid should be mixed for use at the moment so as to avoid affecting the painting quality due to too long time;

q3) the strength of the epoxy mortar is C50, after the epoxy mortar is mixed, the epoxy mortar is smeared on a base surface which is brushed with base liquid and is compacted by force, particularly, corner joints need to be compacted repeatedly, so that cavities or gaps are avoided, and after the epoxy mortar leveling layer is constructed, maintenance is needed.

6. The precast column connection deck construction method according to claim 1, wherein: in the step S6, the thickness of each layer of the concrete is controlled to be 20-30 cm when the concrete is subjected to layered vibration.

Technical Field

The invention relates to the technical field of building construction, in particular to a construction method for a prefabricated pile and a prefabricated column connecting bearing platform.

Background

The precast pile is prefabricated in site at or near the piling site, and the shorter pile may be produced in prefabricating plant.

However, in the prior art, in the construction process of a precast pile, due to poor sealing performance of the pile body, other objects are mixed into the pile body, and the overall density of the pile body is further influenced, so that the stability of the pile body is poor, and secondly, in the construction process, in the installation process of the traditional precast pier column, positioning is not carried out through any auxiliary tool, so that the conditions of time and labor waste and poor positioning precision in the installation process are caused, the repeated construction condition is easily caused, and the construction efficiency is influenced, so that the construction method for connecting the precast pile and the precast column with the bearing platform is provided.

Disclosure of Invention

The invention aims to solve the defects in the prior art and provides a construction method for connecting a precast pile and a precast column with a bearing platform.

In order to achieve the purpose, the invention adopts the following technical scheme: the construction method of the precast pile and the precast column connecting bearing platform comprises the following steps:

s1, preparing a prefabricated tubular pile, which specifically comprises the following steps: after the pile top meets the requirement of design elevation, the connection of the tubular pile and the bearing platform can be constructed according to a design drawing, before pouring core filling C50 micro-expansion concrete, the inner wall of the tubular pile is cleaned up by floating slurry, measures such as coating cement paste on the inner wall, concrete interface agent or micro-expansion concrete are adopted to improve the integrity of the core filling concrete and the concrete of the pile body of the tubular pile, a supporting plate is arranged and a framework is placed, a main rib connected in the pile is firmly welded with a tubular pile end connecting plate, and a welding seam meets the requirement of design specification;

s2, excavating a foundation pit of the bearing platform, and pouring a cushion layer, wherein the method specifically comprises the following steps: excavating a foundation pit to a designed elevation, performing circular cutting on a pile head by using a concrete cutting machine, cutting the pile head to the designed elevation, cleaning and trimming a pile body reinforcing steel bar extending into a bearing platform into a designed shape, re-measuring the elevation of the pile top, performing pile foundation detection, entering the next procedure after the pile body reinforcing steel bar is qualified, manually leveling after mechanical excavation is completed, pouring a concrete cushion layer according to the requirement of a design drawing to be used as a bottom mould of a structure, wherein the top surface of the concrete cushion layer is not higher than the elevation of a base, and the edge of the concrete cushion layer extends out of the edge of the bearing platform by 20 cm;

s3, precast tubular pile core filling concrete construction: in order to ensure the integrity and structural stress of the bearing platform and the prefabricated pipe pile, core filling reinforced concrete construction is carried out on the prefabricated pipe pile top by 4m, and the pipe pile is cleaned → the steel bar and the supporting plate are processed → the mould is hung and installed → the core filling concrete is poured;

s4, binding of a bearing platform and a cup opening reinforcing steel bar: the semi-finished products of the reinforcing steel bars are processed in a centralized way in a reinforcing steel bar processing factory, and the processed semi-finished products are transported to a construction site by a transport vehicle for installation;

s5, installing a bearing platform and a cup opening template: processing and installing a template after finishing processing and installing bearing platform steel bars and reporting and testing, wherein the bearing platform adopts a shaped steel mould or a wood mould with the thickness not less than 18mm, four angular points and axes at the positions of the bearing platform and a central positioning block are measured and discharged during template installation, the template is erected according to a control point, the erection of the template is accurate, particularly the geometric dimension and the axis position of the template, the template is firmly fixed, a specially-assigned person is required to inspect the template during concrete pouring, the position of the template is ensured not to deform, the template is not run, slurry is not leaked and misplaced, in addition, color-painting oil is required to be brushed before the template is erected, the engineering quality reaches the internal beauty and the external beauty, after the template installation is qualified according to the requirements, sundries in the template are cleaned, a supervision engineer is informed to check and accept, and the preparation work for pouring concrete is carried out;

s6, pouring concrete on the bearing platform and the cup rim positioning block: the working performance of concrete is strictly controlled in the pouring process, the concrete is prevented from separating, the concrete is continuously poured in a layered mode, the layered vibration is carried out, the one-step forming is carried out, the concentrated material piling is strictly forbidden, the side pressure of a local template of a substrate is prevented from being large, the concrete is prevented from obviously layering in appearance, the layering interval pouring time does not exceed the initial setting time of the concrete determined by a test, an insertion type vibrator is adopted for vibrating and compacting all the concrete (particularly gaps between reinforcing steel bars and the template and dense positions of the reinforcing steel bars), a vibrating rod is kept at a distance of 5-10 cm from a side mold, a lower layer concrete is inserted into the vibrating rod for 5-10 cm, the continuity between the upper layer concrete and the lower layer concrete is kept, insertion points are uniform during vibration, the vibrating rod advances in a line or in a staggered mode, the moving distance is not more than 1.5 times of the acting radius of the vibrating rod so as to avoid over-vibration or leakage-vibration, the vibrating rod is pulled out while vibrating after each vibration, the vibrating rod is not inclined or transverse, strictly forbidding to stop vibrating, pulling out the rod to avoid causing the concrete to have a cavity, taking the concrete as the concrete is not sunk any more and no bubble emerges, and paying attention to not touch and loosen the template or shift the reinforcing steel bar during vibrating, wherein in the process, a laboratory needs to detect the workability of the concrete at any time, pour the concrete when the workability meets the requirements, leave and take test pieces according to the specifications, and put a group of test pieces and a bearing platform to be cured at the same time under the same curing condition;

s7, backfilling a foundation pit of the bearing platform: when the bearing platform reaches the life-preserving period, the bearing platform is required to be refilled in time, symmetrical layered refilling and compaction are carried out during refilling, foundation pit refilling is carried out twice, the construction of the upright column is not influenced by the first refilling, all the bearing platform is refilled after the construction of the pier column is finished, the refilling ground is slightly higher than the original ground at the periphery, the problem that the pit is accumulated with water is avoided, the bearing platform is soaked, and the two sides are symmetrically carried out during refilling, so that the structure is prevented from being damaged by bias voltage or the stability and the use function of the structure are influenced;

s8, cleaning a cup opening of a bearing platform and constructing a C50 epoxy mortar leveling layer: before the prefabricated pier is installed, an axial cross line is arranged on the top surface of a poured bearing platform in a bouncing mode and serves as a reference line for pier column installation, and meanwhile whether the position of a positioning block and the elevation of the bottom of a cup opening are within a required range or not is checked;

s9, mounting the prefabricated pier stud:

s9.1) the prefabricated pier is lifted and then placed on the geotextile, so that secondary pollution caused by ground contact is avoided. Then cleaning the pier body, wherein a watering cart is used for cleaning, firstly, preliminarily cleaning the pier body, then cleaning the pier body by using a brush, and wiping the pier body by using a rag after cleaning;

s9.2) hoisting the prefabricated pier needs to select hoisting machinery meeting the site construction requirements for hoisting operation, the hoisting operation is directed by a special person, and an interphone is used for directing a truck crane driver, site operators and operators for adjusting the verticality, so that the hoisting safety is ensured;

s9.3) checking the installation verticality of the pier stud: the verticality of the prefabricated pier can be controlled by a vertical angle, namely the verticality of the prefabricated pier is adjusted by theodolites in two directions (forming a 90-degree angle with each other), and the prefabricated pier is frequently leveled in the measurement process to keep vertical;

s9.4) arranging 4 guy cables on each pier column, wherein an included angle between each guy cable and the ground is 45 degrees, and controlling the verticality of the pier columns and the stability of the pier columns before concrete pouring by adjusting the guy cables;

s10, post-pouring concrete construction of the cup mouth of the bearing platform: after the pier stud is installed, after the pier stud is inspected to be qualified, pouring concrete in the cup mouth, wherein the designed strength of the concrete in the cup mouth is C40, pouring the concrete by adopting a sliding chute is slowly placed in the cup mouth, the periphery of the concrete is symmetrically and uniformly poured, the concrete is vibrated in a layered mode until the top of a pouring cushion cap is flush, and the cup mouth concrete covering cotton quilt constructed in winter is maintained.

As a preferred embodiment, the precast pile is composed of a precast tubular pile, a steel plate suspension mould, a precast pier, a pier stud and a guy rope.

As a preferred embodiment, the specific construction steps in step S3 are as follows:

a) and the floating slurry on the inner wall of the precast tubular pile is cleaned up without mud, sand and accumulated water.

b) The connection of the pile top of the pile splicing and pile cutting and the bearing platform meets the design specification and the drawing requirements. c) And cleaning the pile core, and reducing the pile core to below 4m of the pile top if accumulated water exists in the pile core. d) And the processed steel plate hanging die is placed in the tubular pile for controlling the size of the inserted pile and is fixed by adopting a cross reinforcing steel bar frame. e) And after the hanging die is installed, pouring core concrete, wherein the concrete is required to be vibrated tightly but not excessively vibrated when the concrete is poured.

As a preferred embodiment, the specific construction steps in step S4 are as follows:

A) before the bearing platform is blanked, the steel bars must be straightened, the blanking size must be executed after being strictly checked by construction technicians, the steel bars are manufactured and bent into semi-finished products by machining in a steel bar processing factory uniformly, and the bending angle and the length of the straight part are ensured. After the processing is finished, the processed framework is orderly stacked according to the classification of the specification and the variety, and replacement workers cannot be mistakenly taken and misplaced when taking the framework, so that the accuracy of the formed framework is ensured.

B) The steel bar framework binding method is preferably a cross-shaped buckle binding method, a forward buckle is not required to be adopted, the steel bar deformation is prevented, and core filling reinforced concrete construction is carried out on the prefabricated pipe pile top 4m in order to ensure the integrity and structural stress of the bearing platform and the prefabricated pipe pile.

As a preferred embodiment, the specific construction steps in step S8 are as follows:

q1) chiseling the concrete at the bottom of the cup mouth, and cleaning loose particles and dust after chiseling.

Q2) and uniformly coating the base liquid of the epoxy mortar on the bottom of the cup mouth by using a brush, wherein the base liquid is required to be brushed as thin and uniform as possible without flowing or leaking. The base liquid should be mixed for use immediately to avoid affecting the painting quality due to too long time.

Q3) the strength of the epoxy mortar is C50, after the epoxy mortar is mixed, the epoxy mortar is smeared on a base surface which is brushed with base liquid and is compacted by force, particularly, corner joints need to be compacted repeatedly, so that cavities or gaps are avoided, and after the epoxy mortar leveling layer is constructed, maintenance is needed.

In a preferred embodiment, in step S6, the thickness of each layer of the concrete is controlled to be 20 to 30cm when the concrete is vibrated in layers.

Compared with the prior art, the invention has the advantages and positive effects that,

1. according to the invention, the cup opening positioning block is adopted to improve the installation positioning precision and the construction precision of the pier stud, and simultaneously improve the overall stability and the anti-overturning effect of the pier stud.

2. In the invention, in the process of C50 epoxy mortar leveling layer construction, the epoxy mortar is smeared on the base surface which is brushed with the base liquid, and the bottom end of the pier stud is pressed by force, particularly the corner joints are pressed repeatedly to avoid the occurrence of holes or gaps, and by the design, the epoxy mortar leveling layer can improve the sealing property of the bottom end of the pier stud, meanwhile, the positioning verticality of the pier stud is improved, the condition that the mounting verticality does not meet the requirement due to the uneven cup mouth or the uneven bottom end of the pier stud is prevented, the sealing performance of the bottom end of the pier stud is improved, liquid or other objects can be effectively prevented from being mixed into the interior of the pier stud through gaps, further causing the components of the pier column not to reach the standard, further causing the overall density of the pier column to be different, affecting the overall stability of the pier column, secondly, improve the location straightness that hangs down of pier stud, can conveniently seek the perpendicular setpoint of pier stud to be under construction, and then promote the efficiency of construction.

3. In the invention, in the installation process of the prefabricated pier stud, each pier stud is provided with 4 cable ropes, the included angle between each cable rope and the ground is 45 degrees, the verticality of the pier stud and the stability before concrete pouring are controlled by adjusting the cable ropes, and the safety and verticality control of the construction of the prefabricated pier stud can be improved by the design that the cable ropes are used for assisting the positioning of the prefabricated pier stud.

4. In the invention, in the construction process of pouring concrete after the cup opening of the bearing platform, concrete pouring is slowly placed into the cup opening by adopting a sliding groove, the periphery of the cup opening is symmetrically and uniformly poured, and the pouring is carried out in a layered mode until the top of the pouring bearing platform is flush, and in the design, the lower end of the prefabricated pier stud is anchored into the bearing platform, and the inner part of the prefabricated pier stud is provided with a shear groove: the contact surface of the stressed area is increased, the post-cast concrete connection with the bearing platform is enhanced, the anti-cracking performance, the anti-shearing performance and the occlusion capacity of the prefabricated pier stud are increased, and the stability of the prefabricated pier stud is improved.

Drawings

FIG. 1 is a front view of a precast pile according to the construction method of a precast pile and a precast column connection cap according to the present invention;

FIG. 2 is a side view of a precast pile according to the construction method of the precast pile and a precast column connection cap according to the present invention;

FIG. 3 is a plan view of a precast pile according to the construction method of the precast pile and a precast column connection cap according to the present invention;

fig. 4 is a construction drawing of step S1 in the construction method of the precast pile and the precast column connection cap according to the present invention;

fig. 5 is a construction drawing of step S2 in the construction method of the precast pile and the precast column connection cap according to the present invention;

fig. 6 is a construction drawing of step S3 in the construction method of the precast pile and the precast column connection cap according to the present invention;

fig. 7 is a construction drawing of step S4 in the construction method of the precast pile and the precast column connection cap according to the present invention;

fig. 8 is a construction drawing of step S5 in the construction method of the precast pile and the precast column connection cap according to the present invention;

fig. 9 is a construction drawing of step S6 in the construction method of the precast pile and the precast column connecting cap according to the present invention;

fig. 10 is a construction drawing of step S7 in the construction method of the precast pile and the precast column connecting cap according to the present invention;

fig. 11 is a construction drawing of step S8 in the construction method of the precast pile and the precast column connecting cap according to the present invention;

fig. 12 is a construction drawing of step S9 in the construction method of the precast pile and the precast column connecting cap according to the present invention;

fig. 13 is a construction drawing of step S10 in the construction method of the precast pile and the precast column connecting cap according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

As shown in fig. 1 to 13, the present invention provides a technical solution: the construction method of the precast pile and the precast column connecting bearing platform comprises the following steps:

s1, preparing a prefabricated tubular pile, which specifically comprises the following steps: after the pile top meets the requirement of design elevation, the connection of the tubular pile and the bearing platform can be constructed according to a design drawing, before pouring core filling C50 micro-expansion concrete, the inner wall of the tubular pile is cleaned up by floating slurry, measures such as coating cement paste on the inner wall, concrete interface agent or micro-expansion concrete are adopted to improve the integrity of the core filling concrete and the concrete of the pile body of the tubular pile, a supporting plate is arranged and a framework is placed, a main rib connected in the pile is firmly welded with a tubular pile end connecting plate, and a welding seam meets the requirement of design specification;

s2, excavating a foundation pit of the bearing platform, and pouring a cushion layer, wherein the method specifically comprises the following steps: excavating a foundation pit to a designed elevation, performing circular cutting on a pile head by using a concrete cutting machine, cutting the pile head to the designed elevation, cleaning and trimming a pile body reinforcing steel bar extending into a bearing platform into a designed shape, re-measuring the elevation of the pile top, performing pile foundation detection, entering the next procedure after the pile body reinforcing steel bar is qualified, manually leveling after mechanical excavation is completed, pouring a concrete cushion layer according to the requirement of a design drawing to be used as a bottom mould of a structure, wherein the top surface of the concrete cushion layer is not higher than the elevation of a base, and the edge of the concrete cushion layer extends out of the edge of the bearing platform by 20 cm;

s3, precast tubular pile core filling concrete construction: in order to ensure the integrity and structural stress of the bearing platform and the prefabricated pipe pile, core filling reinforced concrete construction is carried out on the prefabricated pipe pile top by 4m, and the pipe pile is cleaned → the steel bar and the supporting plate are processed → the mould is hung and installed → the core filling concrete is poured;

s4, binding of a bearing platform and a cup opening reinforcing steel bar: the semi-finished products of the reinforcing steel bars are processed in a centralized way in a reinforcing steel bar processing factory, and the processed semi-finished products are transported to a construction site by a transport vehicle for installation;

s5, installing a bearing platform and a cup opening template: processing and installing a template after finishing processing and installing bearing platform steel bars and reporting and testing, wherein the bearing platform adopts a shaped steel mould or a wood mould with the thickness not less than 18mm, four angular points and axes at the positions of the bearing platform and a central positioning block are measured and discharged during template installation, the template is erected according to a control point, the erection of the template is accurate, particularly the geometric dimension and the axis position of the template, the template is firmly fixed, a specially-assigned person is required to inspect the template during concrete pouring, the position of the template is ensured not to deform, the template is not run, slurry is not leaked and misplaced, in addition, color-painting oil is required to be brushed before the template is erected, the engineering quality reaches the internal beauty and the external beauty, after the template installation is qualified according to the requirements, sundries in the template are cleaned, a supervision engineer is informed to check and accept, and the preparation work for pouring concrete is carried out;

s6, pouring concrete on the bearing platform and the cup rim positioning block: the working performance of concrete is strictly controlled in the pouring process, the concrete is prevented from separating, the concrete is continuously poured in a layered mode, the layered vibration is carried out, the one-step forming is carried out, the concentrated material piling is strictly forbidden, the side pressure of a local template of a substrate is prevented from being large, the concrete is prevented from obviously layering in appearance, the layering interval pouring time does not exceed the initial setting time of the concrete determined by a test, an insertion type vibrator is adopted for vibrating and compacting all the concrete (particularly gaps between reinforcing steel bars and the template and dense positions of the reinforcing steel bars), a vibrating rod is kept at a distance of 5-10 cm from a side mold, a lower layer concrete is inserted into the vibrating rod for 5-10 cm, the continuity between the upper layer concrete and the lower layer concrete is kept, insertion points are uniform during vibration, the vibrating rod advances in a line or in a staggered mode, the moving distance is not more than 1.5 times of the acting radius of the vibrating rod so as to avoid over-vibration or leakage-vibration, the vibrating rod is pulled out while vibrating after each vibration, the vibrating rod is not inclined or transverse, strictly forbidding to stop vibrating, pulling out the rod to avoid causing the concrete to have a cavity, taking the concrete as the concrete is not sunk any more and no bubble emerges, and paying attention to not touch and loosen the template or shift the reinforcing steel bar during vibrating, wherein in the process, a laboratory needs to detect the workability of the concrete at any time, pour the concrete when the workability meets the requirements, leave and take test pieces according to the specifications, and put a group of test pieces and a bearing platform to be cured at the same time under the same curing condition;

s7, backfilling a foundation pit of the bearing platform: when the bearing platform reaches the life-preserving period, the bearing platform is required to be refilled in time, symmetrical layered refilling and compaction are carried out during refilling, foundation pit refilling is carried out twice, the construction of the upright column is not influenced by the first refilling, all the bearing platform is refilled after the construction of the pier column is finished, the refilling ground is slightly higher than the original ground at the periphery, the problem that the pit is accumulated with water is avoided, the bearing platform is soaked, and the two sides are symmetrically carried out during refilling, so that the structure is prevented from being damaged by bias voltage or the stability and the use function of the structure are influenced;

s8, cleaning a cup opening of a bearing platform and constructing a C50 epoxy mortar leveling layer: before the prefabricated pier is installed, an axial cross line is arranged on the top surface of a poured bearing platform in a bouncing mode and serves as a reference line for pier column installation, and meanwhile whether the position of a positioning block and the elevation of the bottom of a cup opening are within a required range or not is checked;

s9, mounting the prefabricated pier stud:

s9.1) the prefabricated pier is lifted and then placed on the geotextile, so that secondary pollution caused by ground contact is avoided. Then cleaning the pier body, wherein a watering cart is used for cleaning, firstly, preliminarily cleaning the pier body, then cleaning the pier body by using a brush, and wiping the pier body by using a rag after cleaning;

s9.2) hoisting the prefabricated pier needs to select hoisting machinery meeting the site construction requirements for hoisting operation, the hoisting operation is directed by a special person, and an interphone is used for directing a truck crane driver, site operators and operators for adjusting the verticality, so that the hoisting safety is ensured;

s9.3) checking the installation verticality of the pier stud: the verticality of the prefabricated pier can be controlled by a vertical angle, namely the verticality of the prefabricated pier is adjusted by theodolites in two directions (forming a 90-degree angle with each other), and the prefabricated pier is frequently leveled in the measurement process to keep vertical;

s9.4) arranging 4 guy cables on each pier column, wherein an included angle between each guy cable and the ground is 45 degrees, and controlling the verticality of the pier columns and the stability of the pier columns before concrete pouring by adjusting the guy cables;

s10, post-pouring concrete construction of the cup mouth of the bearing platform: after the pier stud is installed, after the pier stud is inspected to be qualified, pouring concrete in the cup mouth, wherein the designed strength of the concrete in the cup mouth is C40, pouring the concrete by adopting a sliding chute is slowly placed in the cup mouth, the periphery of the concrete is symmetrically and uniformly poured, the concrete is vibrated in a layered mode until the top of a pouring cushion cap is flush, and the cup mouth concrete covering cotton quilt constructed in winter is maintained.

As a preferred embodiment, the precast pile is composed of a precast tubular pile, a steel plate suspension mould, a precast pier, a pier stud and a guy rope.

As a preferred embodiment, the specific construction steps in step S3 are as follows:

a) and the floating slurry on the inner wall of the precast tubular pile is cleaned up without mud, sand and accumulated water.

b) The connection of the pile top of the pile splicing and pile cutting and the bearing platform meets the design specification and the drawing requirements. c) And cleaning the pile core, and reducing the pile core to below 4m of the pile top if accumulated water exists in the pile core. d) And the processed steel plate hanging die is placed in the tubular pile for controlling the size of the inserted pile and is fixed by adopting a cross reinforcing steel bar frame. e) And after the hanging die is installed, pouring core concrete, wherein the concrete is required to be vibrated tightly but not excessively vibrated when the concrete is poured.

As a preferred embodiment, the specific construction steps in step S4 are as follows:

A) before the bearing platform is blanked, the steel bars must be straightened, the blanking size must be executed after being strictly checked by construction technicians, the steel bars are manufactured and bent into semi-finished products by machining in a steel bar processing factory uniformly, and the bending angle and the length of the straight part are ensured. After the processing is finished, the processed framework is orderly stacked according to the classification of the specification and the variety, and replacement workers cannot be mistakenly taken and misplaced when taking the framework, so that the accuracy of the formed framework is ensured.

B) The steel bar framework binding method is preferably a cross-shaped buckle binding method, a forward buckle is not required to be adopted, the steel bar deformation is prevented, and core filling reinforced concrete construction is carried out on the prefabricated pipe pile top 4m in order to ensure the integrity and structural stress of the bearing platform and the prefabricated pipe pile.

As a preferred embodiment, the specific construction steps in step S8 are as follows:

q1) chiseling the concrete at the bottom of the cup mouth, and cleaning loose particles and dust after chiseling.

Q2) and uniformly coating the base liquid of the epoxy mortar on the bottom of the cup mouth by using a brush, wherein the base liquid is required to be brushed as thin and uniform as possible without flowing or leaking. The base liquid should be mixed for use immediately to avoid affecting the painting quality due to too long time.

Q3) the strength of the epoxy mortar is C50, after the epoxy mortar is mixed, the epoxy mortar is smeared on a base surface which is brushed with base liquid and is compacted by force, particularly, corner joints need to be compacted repeatedly, so that cavities or gaps are avoided, and after the epoxy mortar leveling layer is constructed, maintenance is needed.

In a preferred embodiment, in step S6, the thickness of each layer of the concrete is controlled to be 20 to 30cm when the concrete is vibrated in layers.

Comparative example 1

This example is substantially the same as the method of example 1 provided, with the main differences being: in the step S6, the cup rim positioning block is not adopted for concrete pouring;

comparative example 2

This example is substantially the same as the method of example 1 provided, with the main differences being: in step S8, C50 epoxy mortar leveling layer construction is not performed.

Comparative example 3

This example is substantially the same as the method of example 1 provided, with the main differences being: in step S9, the hawser is not used.

Construction progress testing

The accuracy, the progress efficiency and the rework times of the data of the construction method for the precast column connection bearing platform provided by the embodiment 1 and the comparative examples 1 to 3 are respectively taken in equal amounts:

	accuracy of	Progress efficiency	Number of reworking operations
				Example 1	99.99%	100%	0
Comparative example 1	99.92%	80%	2
				Comparative example 2	99.95%	90%	3
Comparative example 3	99.93%	70%	2

According to the construction method, the construction method for the prefabricated pile and the prefabricated column connecting bearing platform comprises the following steps:

s1, preparing a prefabricated tubular pile, which specifically comprises the following steps: after the pile top meets the requirement of design elevation, the connection of the tubular pile and the bearing platform can be constructed according to a design drawing, before pouring core filling C50 micro-expansion concrete, the inner wall of the tubular pile is cleaned up by floating slurry, measures such as coating cement paste on the inner wall, concrete interface agent or micro-expansion concrete are adopted to improve the integrity of the core filling concrete and the concrete of the pile body of the tubular pile, a supporting plate is arranged and a framework is placed, a main rib connected in the pile is firmly welded with a tubular pile end connecting plate, and a welding seam meets the requirement of design specification;

s2, excavating a foundation pit of the bearing platform, and pouring a cushion layer, wherein the method specifically comprises the following steps: excavating a foundation pit to a designed elevation, performing circular cutting on a pile head by using a concrete cutting machine, cutting the pile head to the designed elevation, cleaning and trimming a pile body reinforcing steel bar extending into a bearing platform into a designed shape, re-measuring the elevation of the pile top, performing pile foundation detection, entering the next procedure after the pile body reinforcing steel bar is qualified, manually leveling after mechanical excavation is completed, pouring a concrete cushion layer according to the requirement of a design drawing to be used as a bottom mould of a structure, wherein the top surface of the concrete cushion layer is not higher than the elevation of a base, and the edge of the concrete cushion layer extends out of the edge of the bearing platform by 20 cm;

s3, precast tubular pile core filling concrete construction: in order to ensure the integrity and structural stress of the bearing platform and the prefabricated pipe pile, core filling reinforced concrete construction is carried out on the prefabricated pipe pile top by 4m, and the pipe pile is cleaned → the steel bar and the supporting plate are processed → the mould is hung and installed → the core filling concrete is poured;

s4, binding of a bearing platform and a cup opening reinforcing steel bar: the semi-finished products of the reinforcing steel bars are processed in a centralized way in a reinforcing steel bar processing factory, and the processed semi-finished products are transported to a construction site by a transport vehicle for installation;

s5, installing a bearing platform and a cup opening template: processing and installing a template after finishing processing and installing bearing platform steel bars and reporting and testing, wherein the bearing platform adopts a shaped steel mould or a wood mould with the thickness not less than 18mm, four angular points and axes at the positions of the bearing platform and a central positioning block are measured and discharged during template installation, the template is erected according to a control point, the erection of the template is accurate, particularly the geometric dimension and the axis position of the template, the template is firmly fixed, a specially-assigned person is required to inspect the template during concrete pouring, the position of the template is ensured not to deform, the template is not run, slurry is not leaked and misplaced, in addition, color-painting oil is required to be brushed before the template is erected, the engineering quality reaches the internal beauty and the external beauty, after the template installation is qualified according to the requirements, sundries in the template are cleaned, a supervision engineer is informed to check and accept, and the preparation work for pouring concrete is carried out;

s6, pouring concrete on the bearing platform and the cup rim positioning block: the working performance of concrete is strictly controlled in the pouring process, the concrete is prevented from separating, the concrete is continuously poured in a layered mode, the layered vibration is carried out, the one-step forming is carried out, the concentrated material piling is strictly forbidden, the side pressure of a local template of a substrate is prevented from being large, the concrete is prevented from obviously layering in appearance, the layering interval pouring time does not exceed the initial setting time of the concrete determined by a test, an insertion type vibrator is adopted for vibrating and compacting all the concrete (particularly gaps between reinforcing steel bars and the template and dense positions of the reinforcing steel bars), a vibrating rod is kept at a distance of 5-10 cm from a side mold, a lower layer concrete is inserted into the vibrating rod for 5-10 cm, the continuity between the upper layer concrete and the lower layer concrete is kept, insertion points are uniform during vibration, the vibrating rod advances in a line or in a staggered mode, the moving distance is not more than 1.5 times of the acting radius of the vibrating rod so as to avoid over-vibration or leakage-vibration, the vibrating rod is pulled out while vibrating after each vibration, the vibrating rod is not inclined or transverse, strictly forbidding to stop vibrating, pulling out the rod to avoid causing the concrete to have a cavity, taking the concrete as the concrete is not sunk any more and no bubble emerges, and paying attention to not touch and loosen the template or shift the reinforcing steel bar during vibrating, wherein in the process, a laboratory needs to detect the workability of the concrete at any time, pour the concrete when the workability meets the requirements, leave and take test pieces according to the specifications, and put a group of test pieces and a bearing platform to be cured at the same time under the same curing condition;

s7, backfilling a foundation pit of the bearing platform: when the bearing platform reaches the life-preserving period, the bearing platform is required to be refilled in time, symmetrical layered refilling and compaction are carried out during refilling, foundation pit refilling is carried out twice, the construction of the upright column is not influenced by the first refilling, all the bearing platform is refilled after the construction of the pier column is finished, the refilling ground is slightly higher than the original ground at the periphery, the problem that the pit is accumulated with water is avoided, the bearing platform is soaked, and the two sides are symmetrically carried out during refilling, so that the structure is prevented from being damaged by bias voltage or the stability and the use function of the structure are influenced;

s8, cleaning a cup opening of a bearing platform and constructing a C50 epoxy mortar leveling layer: before the prefabricated pier is installed, an axial cross line is arranged on the top surface of a poured bearing platform in a bouncing mode and serves as a reference line for pier column installation, and meanwhile whether the position of a positioning block and the elevation of the bottom of a cup opening are within a required range or not is checked;

s9, mounting the prefabricated pier stud:

s9.1) the prefabricated pier is lifted and then placed on the geotextile, so that secondary pollution caused by ground contact is avoided. Then cleaning the pier body, wherein a watering cart is used for cleaning, firstly, preliminarily cleaning the pier body, then cleaning the pier body by using a brush, and wiping the pier body by using a rag after cleaning;

s9.2) hoisting the prefabricated pier needs to select hoisting machinery meeting the site construction requirements for hoisting operation, the hoisting operation is directed by a special person, and an interphone is used for directing a truck crane driver, site operators and operators for adjusting the verticality, so that the hoisting safety is ensured;

s9.3) checking the installation verticality of the pier stud: the verticality of the prefabricated pier can be controlled by a vertical angle, namely the verticality of the prefabricated pier is adjusted by theodolites in two directions (forming a 90-degree angle with each other), and the prefabricated pier is frequently leveled in the measurement process to keep vertical;

s9.4) arranging 4 guy cables on each pier column, wherein an included angle between each guy cable and the ground is 45 degrees, and controlling the verticality of the pier columns and the stability of the pier columns before concrete pouring by adjusting the guy cables;

s10, post-pouring concrete construction of the cup mouth of the bearing platform: after the pier stud is installed, after the pier stud is inspected to be qualified, pouring concrete in the cup mouth, wherein the designed strength of the concrete in the cup mouth is C40, pouring the concrete by adopting a sliding chute is slowly placed in the cup mouth, the periphery of the concrete is symmetrically and uniformly poured, the concrete is vibrated in a layered mode until the top of a pouring cushion cap is flush, and the cup mouth concrete covering cotton quilt constructed in winter is maintained.

As a preferred embodiment, the precast pile is composed of a precast tubular pile, a steel plate suspension mould, a precast pier, a pier stud and a guy rope.

As a preferred embodiment, the specific construction steps in step S3 are as follows:

a) and the floating slurry on the inner wall of the precast tubular pile is cleaned up without mud, sand and accumulated water.

b) The connection of the pile top of the pile splicing and pile cutting and the bearing platform meets the design specification and the drawing requirements. c) And cleaning the pile core, and reducing the pile core to below 4m of the pile top if accumulated water exists in the pile core. d) And the processed steel plate hanging die is placed in the tubular pile for controlling the size of the inserted pile and is fixed by adopting a cross reinforcing steel bar frame. e) And after the hanging die is installed, pouring core concrete, wherein the concrete is required to be vibrated tightly but not excessively vibrated when the concrete is poured.

As a preferred embodiment, the specific construction steps in step S4 are as follows:

A) before the bearing platform is blanked, the steel bars must be straightened, the blanking size must be executed after being strictly checked by construction technicians, the steel bars are manufactured and bent into semi-finished products by machining in a steel bar processing factory uniformly, and the bending angle and the length of the straight part are ensured. After the processing is finished, the processed framework is orderly stacked according to the classification of the specification and the variety, and replacement workers cannot be mistakenly taken and misplaced when taking the framework, so that the accuracy of the formed framework is ensured.

B) The steel bar framework binding method is preferably a cross-shaped buckle binding method, a forward buckle is not required to be adopted, the steel bar deformation is prevented, and core filling reinforced concrete construction is carried out on the prefabricated pipe pile top 4m in order to ensure the integrity and structural stress of the bearing platform and the prefabricated pipe pile.

As a preferred embodiment, the specific construction steps in step S8 are as follows:

q1) chiseling the concrete at the bottom of the cup mouth, and cleaning loose particles and dust after chiseling.

Q2) and uniformly coating the base liquid of the epoxy mortar on the bottom of the cup mouth by using a brush, wherein the base liquid is required to be brushed as thin and uniform as possible without flowing or leaking. The base liquid should be mixed for use immediately to avoid affecting the painting quality due to too long time.

Q3) the strength of the epoxy mortar is C50, after the epoxy mortar is mixed, the epoxy mortar is smeared on a base surface which is brushed with base liquid and is compacted by force, particularly, corner joints need to be compacted repeatedly, so that cavities or gaps are avoided, and after the epoxy mortar leveling layer is constructed, maintenance is needed.

In a preferred embodiment, in step S6, the thickness of each layer of the concrete is controlled to be 20 to 30cm when the concrete is vibrated in layers.

The above description is only a preferred embodiment of the present invention, and not intended to limit the present invention in other forms, and any person skilled in the art may apply the above modifications or changes to the equivalent embodiments with equivalent changes by using the technical contents disclosed in the above description, but all simple modifications, equivalent changes and changes made to the above embodiments according to the technical essence of the present invention will still fall within the protection scope of the technical solution of the present invention.