阅读说明：本技术 一种底泥处理厂用管桩基础的施工方法 (Construction method of tubular pile foundation for bottom mud treatment plant ) 是由 卢驰江 孟祥领 张远金 陈海斌 聂法岭 李彬 张维栋 郭兰军 于 2021-01-15 设计创作，主要内容包括：一种底泥处理厂用管桩基础的施工方法,包括以下步骤：(1)场地平整；(2)现场放线；(3)打桩设备准备；(4)打桩作业；(5)截桩处理；(6)验收。本发明可有效用于底泥处理厂的施工需要,解决底泥处理厂的安全、稳定性的问题,本发明的方法先进、科学,施工速度快,易操作,质量好,抗应变能力强、稳定、安全。(A construction method of a tubular pile foundation for a sediment disposal plant comprises the following steps: (1) leveling the field; (2) paying off on site; (3) preparing a piling device; (4) piling; (5) pile cutting treatment; (6) and (6) checking and accepting. The method can be effectively used for construction requirements of the bottom mud treatment plant, solves the problems of safety and stability of the bottom mud treatment plant, and is advanced, scientific, high in construction speed, easy to operate, good in quality, strong in strain resistance, stable and safe.)

1. A construction method of a tubular pile foundation for a sediment disposal plant is characterized by comprising the following steps:

(1) leveling the field: cleaning various wastes in a pile foundation area, backfilling a foundation to a designed elevation, carrying out earth balance, and leveling a field to meet the pile foundation construction requirement;

(2) and (3) field paying-off: arranging a plurality of pile pre-leveling points near a piling construction area, wherein axis control is arranged 7-8m away from an outer pile to control the axis and elevation of the pile; placing the positioning line of the pile according to the drawing, and pressing outwards from the center to form the pile so as to prevent hole leakage and dislocation; according to the known control points on site, pile position control points are measured and released according to the pile spacing required by design; the pile position measurement and positioning are carried out by adopting theodolite orientation and steel ruler distance measurement;

(3) preparing a piling device: moving the pile driver to the pile position according to the pile driving sequence, aligning the pile position, adjusting the pile driver to be horizontal and stable, and avoiding inclination and movement in construction;

(4) piling: transporting the pipe piles to the site by using a flat car, unloading the pipe piles to one side of a pile machine by using a crane, and stacking the pipe piles according to the piling sequence and the matching requirements of the piles; when the tubular pile is hung to a pile position, the tubular pile is hung to a pile machine clamp and aligned to the pile position, the tubular pile is clamped and placed into the soil, the pile machine is moved to adjust the verticality of the pile, the pile tip is placed into the soil, then the pile machine is adjusted to be horizontal and stable, then the lifting appliance is removed to insert the pile, and the pile tip is pressed into the soil by means of the dead weight and the balance weight of the tubular pile; in the process, the pressure does not exceed the strength of the pile body, and the center lines of the pile cap, the pile body and the pile feeding are coincided; then piling, correcting the verticality of the pile frame guide rod and the pile during piling, and keeping the hammer, the pile tip and the pile on the same longitudinal axis; during pile driving, the pile needs to be driven and welded to be lengthened while the pile is driven, an alternating current welding machine is adopted for welding, groove welding is adopted for pipe pile welding, a lining hoop is placed on a stop block on the inner side of a lower pile section, the inner wall of the pipe pile is tightly attached to the stop block for sectional spot welding, then the upper pile section is hung, a groove is placed on a welding bead, the upper pile section and the lower pile section are kept straight, the dislocation deviation is 0.5-1mm, the verticality is corrected by using a theodolite, and then spot welding; welding is symmetrically carried out, multilayer welding is applied, the welding seam joints of all layers of the tubular pile are staggered, and welding slag is removed from each layer;

(5) pile cutting treatment: arranging a core-pulling machine frame above the tubular pile, and cutting the tubular pile into rings by using a cutting machine without damaging a steel bar framework in the tubular pile during cutting; installing core-pulling equipment on the core-pulling machine, drilling and stripping concrete of the tubular pile through the core-pulling equipment; removing residual concrete on the tubular pile to expose the steel reinforcement framework;

(6) and (6) checking and accepting.

2. The construction method of the tubular pile foundation for the sediment treatment plant according to claim 1, characterized in that a pile test is firstly carried out before the construction of the tubular pile foundation, and the concrete steps are as follows: excavating a foundation pit at a selected position of a selected site; sinking a design pipe pile into a bearing layer of a soil body in the foundation pit, and enabling a gap to be formed between the foundation pit and the pile side of the design pipe pile positioned in the foundation pit; and filling crushed stone with the particle size of 5-6mm in the gap until the crushed stone surrounds the pile side of the designed tubular pile.

3. The construction method of the tubular pile foundation for the sediment disposal plant as claimed in claims 1-2, wherein when the design pile is a tubular pile, the diameter of the positioning pit is greater than 150-200mm of the diameter of the tubular pile.

4. The method for constructing a tubular pile foundation for a sediment disposal plant according to claims 1 to 3, wherein in the step (2), the plurality of control pile pre-leveling points are spaced 45 to 50m from the piling construction area, and after the pile position control points are measured out, the holes are punched by steel rods and marked by pouring lime.

5. The method for constructing a tubular pile foundation for a sediment treatment plant according to claims 1 to 4, wherein in the step (4), the hoisting pile is hoisted by binding a point, the tubular pile is in place and then is subjected to bidirectional perpendicularity correction, when the perpendicularity deviation exceeds 0.5% of the length of a single section of the pile, the pile is stopped and is timely corrected, the perpendicularity of the pile body is ensured, and the elevation is controlled by a GPS (global positioning system) so as to ensure that the elevation of the pile top is consistent with the designed elevation.

6. The construction method of a tubular pile foundation for a bottom mud treatment plant according to claim 5, wherein in the step (4), after the pile tip of the tubular pile is inserted into the pile position, the deviation of verticality of the pile when the pile machine is moved is 0.2-0.3%, the allowable deviation of the pile top is ± 30mm, and the pile machine is in a stable state; the hammer is low-impact when the piling is started, and the height of the falling hammer from the falling hammer is 0.3-0.4 m; each pile is continuously driven once, the two hanging hammers form a 90-degree direction for observation from the front and the side in the piling process, the verticality of the pile is ensured in the piling process, and the deviation of the pile top is controlled to be 2-3 cm.

7. The construction method of the tubular pile foundation for the sediment treatment plant according to the claim 5-6, characterized in that in the step (4), pile splicing is carried out when the pile is pressed to 70-80cm from the ground, the pile tip is prevented from approaching the hard holding layer or being positioned in the middle of the hard holding layer during pile splicing, welding is adopted for pile splicing, water, oil, rust or other dirt in the slope is removed before welding, and anti-rust paint is brushed; when pile splicing is carried out, the periphery is fixed by spot welding and then is symmetrically welded, the deviation of the central lines of the upper pile section and the lower pile section is 4-6mm, and the bending vector of the node is not more than 1% of the pile length.

8. The construction method of the tubular pile foundation for the sediment treatment plant according to claim 7, wherein in the step (5), when pile cutting is not required, the connection of the pile top of the tubular pile without pile cutting and the bearing platform is realized by arranging a first end plate at one end of the tubular pile, arranging a connecting piece on the end plate, welding a connecting rib on the connecting piece, arranging one end part of the end plate on the tubular pile, arranging the connecting rib in the bearing platform, arranging a second end plate at the other end of the tubular pile, arranging an anchoring reinforcing bar inside the second end plate, and arranging concrete between the anchoring reinforcing bar and the second end plate; the connecting ribs and the anchoring reinforcing steel bars are uniformly distributed along the circumferential direction of the tubular pile respectively, and the length of the connecting ribs welded with the connecting pieces is 1/2-3/4 of the diameter of the connecting ribs; and two ends of the anchoring reinforcing steel bar are respectively connected with the first end plate and the second end plate in a welding mode.

Technical Field

The invention belongs to the technical field of pile foundation construction, and particularly relates to a construction method of a tubular pile foundation for a sediment treatment plant.

Background

Along with the development of modern economy and the progress of society, the scale of buildings is continuously enlarged, the depth of foundation treatment is also continuously increased, and the adoption rate of a pile foundation serving as a deep foundation is also continuously improved. According to incomplete statistics, the consumption of piles in China is more than millions and even more, pile foundation projects account for 20% -30% of the cost of common civil engineering, and the proportion of foundation treatment in soft soil areas is higher. China has wide soft soil distribution, and many complex soft soil foundations exist in Bohai Bay, yellow river delta, Yangtze river delta, Zhujiang delta and other coastal areas. Pile foundations are generally adopted when multi-story high-rise buildings, industrial and civil buildings are built on soft soil foundations.

The pile foundation generally needs to penetrate through a weak soil layer, and the soil layer with good soil quality is used as a pile end bearing layer. Pile foundations play an increasingly important role as a deep foundation form. The prestressed concrete pipe pile is one of pile foundations, and people create a plurality of different pile types aiming at different geological conditions, such as a steel pipe pile, a concrete square pile, a concrete round pile, a hole digging pile, a drilled pile, a cast-in-place pile and the like. The pipe piles are classified into prestressed concrete pipe piles and prestressed high-strength concrete pipe piles according to the concrete strength grade or effective pre-stress. The code of the prestressed concrete pipe pile is PC, and the concrete strength of the PC pile is not lower than C60.

The foundation treatment of the bottom mud treatment plant in the soft soil area usually adopts a sheet pile type reinforced concrete structure, but the prior foundation treatment construction method of the bottom mud treatment plant has the defects of large on-site labor amount, long construction period, large influence of on-site construction quality on the mechanical property of the structure and the like. Therefore, in order to improve the integrity and the seismic performance of the foundation of a sediment treatment plant and simultaneously improve the construction efficiency and the construction precision, a tubular pile construction process is needed to meet the requirements of simplicity, convenience in construction and the like.

Disclosure of Invention

In order to solve the problems, the invention provides a construction method of a tubular pile foundation for a sediment disposal plant. The method can be effectively used for construction requirements of the bottom mud treatment plant, solves the problems of safety and stability of the bottom mud treatment plant, and is advanced, scientific, high in construction speed, easy to operate, good in quality, strong in strain resistance, stable and safe.

The technical scheme adopted by the invention for solving the technical problems is a construction method of a tubular pile foundation for a sediment disposal plant, which comprises the following steps:

(1) leveling the field: cleaning various wastes in a pile foundation area, backfilling a foundation to a designed elevation, carrying out earth balance, and leveling a field to meet the pile foundation construction requirement;

(2) and (3) field paying-off: arranging a plurality of pile pre-leveling points near a piling construction area, wherein axis control is arranged 7-8m away from an outer pile to control the axis and elevation of the pile; placing the positioning line of the pile according to the drawing, and pressing outwards from the center to form the pile so as to prevent hole leakage and dislocation; according to the known control points on site, pile position control points are measured and released according to the pile spacing required by design; the pile position measurement and positioning are carried out by adopting theodolite orientation and steel ruler distance measurement;

(3) preparing a piling device: moving the pile driver to the pile position according to the pile driving sequence, aligning the pile position, adjusting the pile driver to be horizontal and stable, and avoiding inclination and movement in construction;

(4) piling: transporting the pipe piles to the site by using a flat car, unloading the pipe piles to one side of a pile machine by using a crane, and stacking the pipe piles according to the piling sequence and the matching requirements of the piles; when the tubular pile is hung to a pile position, the tubular pile is hung to a pile machine clamp and aligned to the pile position, the tubular pile is clamped and placed into the soil, the pile machine is moved to adjust the verticality of the pile, the pile tip is placed into the soil, then the pile machine is adjusted to be horizontal and stable, then the lifting appliance is removed to insert the pile, and the pile tip is pressed into the soil by means of the dead weight and the balance weight of the tubular pile; in the process, the pressure does not exceed the strength of the pile body, and the center lines of the pile cap, the pile body and the pile feeding are coincided; then piling, correcting the verticality of the pile frame guide rod and the pile during piling, and keeping the hammer, the pile tip and the pile on the same longitudinal axis; during pile driving, the pile needs to be driven and welded to be lengthened while the pile is driven, an alternating current welding machine is adopted for welding, groove welding is adopted for pipe pile welding, a lining hoop is placed on a stop block on the inner side of a lower pile section, the inner wall of the pipe pile is tightly attached to the stop block for sectional spot welding, then the upper pile section is hung, a groove is placed on a welding bead, the upper pile section and the lower pile section are kept straight, the dislocation deviation is 0.5-1mm, the verticality is corrected by using a theodolite, and then spot welding; welding is symmetrically carried out, multilayer welding is applied, the welding seam joints of all layers of the tubular pile are staggered, and welding slag is removed from each layer;

(5) pile cutting treatment: arranging a core-pulling machine frame above the tubular pile, and cutting the tubular pile into rings by using a cutting machine without damaging a steel bar framework in the tubular pile during cutting; installing core-pulling equipment on the core-pulling machine, drilling and stripping concrete of the tubular pile through the core-pulling equipment; removing residual concrete on the tubular pile to expose the steel reinforcement framework;

(6) and (6) checking and accepting.

Preferably, the pile testing is firstly carried out before the construction of the pipe pile foundation, and the concrete steps are as follows: excavating a foundation pit at a selected position of a selected site; sinking a design pipe pile into a bearing layer of a soil body in the foundation pit, and enabling a gap to be formed between the foundation pit and the pile side of the design pipe pile positioned in the foundation pit; and filling crushed stone with the particle size of 5-6mm in the gap until the crushed stone surrounds the pile side of the designed tubular pile.

In any of the above schemes, preferably, when the design pile is a tubular pile, the diameter of the positioning pit is greater than 150-200mm of the diameter of the tubular pile.

In any of the above schemes, in the step (2), the distance between the plurality of pile pre-leveling points and the piling construction area is preferably 45-50m, and after the pile position control points are measured, the holes are punched by steel drill rods, and the holes are marked by pouring lime.

Preferably in any one of the above schemes in step (4), hang the stake and adopt a little ligature to lift by crane, the pipe pile takes one's place the back bidirectional correction straightness that hangs down, finds that the straightness deviation that hangs down surpasss the long 0.5% of single section stake, stops piling and in time corrects, guarantees the pile body straightness that hangs down, controls the elevation with GPS to guarantee that pile bolck elevation is unanimous with the design elevation.

In any of the above schemes, preferably, in the step (4), after the pile tip of the tubular pile is inserted into the pile position, the verticality deviation of the pile is 0.2-0.3% when the pile driver is moved, the pile top allowable deviation is ± 30mm, and the pile driver is in a stable state; the hammer is low-impact when the piling is started, and the height of the falling hammer from the falling hammer is 0.3-0.4 m; each pile is continuously driven once, the two hanging hammers form a 90-degree direction for observation from the front and the side in the piling process, the verticality of the pile is ensured in the piling process, and the deviation of the pile top is controlled to be 2-3 cm.

In any of the above schemes, preferably, in the step (4), pile splicing is performed when the pile is jacked to 70-80cm away from the ground, pile splicing is performed when the pile tip is prevented from approaching a hard holding layer or being positioned in the middle of the hard holding layer, welding is adopted for pile splicing, water, oil, rust or other dirt in a groove is removed before welding, and anti-rust paint is brushed; when pile splicing is carried out, the periphery is fixed by spot welding and then is symmetrically welded, the deviation of the central lines of the upper pile section and the lower pile section is 4-6mm, and the bending vector of the node is not more than 1% of the pile length.

In any of the above schemes, preferably, in the step (5), when pile cutting is not required, the connection between the pile top of the pipe pile without pile cutting and the bearing platform is performed by arranging a first end plate at one end of the pipe pile, arranging a connecting piece on the end plate, welding a connecting rib on the connecting piece, arranging one end part of the end plate and the connecting rib on the pipe pile, and arranging a second end plate at the other end of the pipe pile, arranging an anchoring steel bar inside the pipe pile, and arranging concrete between the anchoring steel bar and the second end plate; the connecting ribs and the anchoring reinforcing steel bars are uniformly distributed along the circumferential direction of the tubular pile respectively, and the length of the connecting ribs welded with the connecting pieces is 1/2-3/4 of the diameter of the connecting ribs; and two ends of the anchoring reinforcing steel bar are respectively connected with the first end plate and the second end plate in a welding mode.

The invention is obtained according to years of practical application practice and experience, adopts the best technical means and measures to carry out combined optimization, obtains the optimal technical effect, is not simple superposition and splicing of technical characteristics, and has obvious significance.

The invention has the beneficial effects that:

1. the method can be effectively used for construction requirements of the bottom mud treatment plant, solves the problems of safety and stability of the bottom mud treatment plant, and is advanced, scientific, high in construction speed, easy to operate, good in quality, strong in strain resistance, stable and safe.

2. Because the thickness and the particle size of the filled crushed stone are known, the frictional resistance characteristic value of the pile side of the designed tubular pile can be determined, the vertical bearing capacity characteristic value of the pile can be accurately calculated, the accuracy of pile testing is improved, the safety and the quality of a building structure are guaranteed, the construction cost of a project is reduced, and the construction period is shortened.

3. The construction method of the invention improves the construction quality of pile foundation engineering, ensures the safety and stability of buildings, effectively improves the construction efficiency, shortens the construction period and reduces the construction cost.

4. The invention has simple operation, labor saving, error rate reduction and convenient construction.

Detailed Description

The invention is further described with reference to specific examples, but the scope of the claims is not limited thereto.

Example 1

A certain bottom mud treatment plant is positioned in a city in south of China, the current situation of the area is a pond, and the total occupied area of the pond is about 8.2 ten thousand meters²The floor area of the bottom mud treatment plant is about 2.55 ten thousand meters². The foundation bears the superstructure load great and foundation soil can not directly be as the bearing stratum, consequently chooses pretensioning method prestressing force high strength concrete tubular pile (PC stake) to consolidate the foundation for use, including 2 regions of dehydration workshop, gas holder tubular pile foundation engineering in the sediment processing factory, also is the important part of constituteing of sediment processing factory.

According to the existing survey data, comprehensive regional data and on-site geological survey, a fourth series artificial filling layer (Q) is distributed in the proposed site^ml) The fourth series of strike layers (Q)^al) Jurassic sedimentary rock (J) argillaceous siltstone can be divided into 5 engineering geological layers from top to bottom according to the cause and substance composition.

(1) Artificial filling (Q) of element of the fourth series₄ ^ml)

Mainly distributed on the ridges between the ponds. The rock core is brown yellow and black, has uniform soil quality, is loose to slightly dense, is dry to wet and is formed by artificial filling, and the conjecture based on field investigation is not disclosed yet.

(2) Mucky soil (Q)^al)

Mainly distributed at the bottom of the pond. The core is gray, grey black, fluid plastic, and has uniform soil texture, and local part contains fine sand or medium coarse sand, and local part can be seen rotten plant rhizome, and has high compressibility and weak water permeability. According to the conventional drilling method, the layer thickness is 0.5-1.3 m, and the average layer thickness is 0.93 m.

(3) The fourth series of residual slope silty clay (Q)^edl)：

The distribution is wide. The rock core is relatively miscellaneous in color, generally yellow brown, brownish red and grey white, and is plastic to hard plastic, is formed by silty sandstone weathering residual slope, is silty cohesive soil and is occasionally highly weathered cobbles. Has medium and high compressibility and weak permeability. According to the conventional drilling method, the layer has a thickness of 3-4.5 m and an average layer thickness of 3.7 m.

(4) Jurassic (J) weathered argillaceous siltstone

The distribution is wide. The rock core is brown yellow and dark gray, the weathering effect of the rock is strong, the rock core is hard soil, the original rock structure is basically destroyed, the rock core is broken easily by hand, the water is softened and disintegrated easily, and the hard block is strongly weathered locally. According to the conventional drilling method, the layer has a thickness of 3.4-4.5 m and an average layer thickness of 3.8 m.

(5) Jurassic (J) strongly weathered argillaceous siltstone

The distribution is wide. The rock core is brown yellow, brown black and brown red, the rock core is broken block and block, the original rock structure is basically destroyed, the rock core is easy to break by hand, and the rock core is easy to soften and disintegrate by soaking in water. According to the drilling exposure, the maximum exposure thickness of the survey is 13.6 m.

Special rock soil

(1) Artificial filling

The artificial filling soil in the exploration range according to the existing exploration results is plain filling soil which has large component and thickness variation, is loose to slightly dense, slightly compacted, unfinished in dead weight consolidation and has uneven physical and mechanical properties, and the dead weight consolidation of the filling soil and the ground settlement and the uneven settlement of buildings (structures) caused by the action of upper load are fully considered.

(2) Mucky soil

The organic fertilizer is mainly distributed at the bottom of a field pond, is gray, gray black, saturated and fluid and plastic, and contains a small amount of organic matters. High water content, large pore ratio, high compressibility, weak water permeability, strong thixotropy and rheological property, and extremely poor engineering property.

(3) Residual soil and weathered rock

The residual soil and the completely weathered argillaceous siltstone are easy to soften and crack when soaked in water, so that the bearing capacity is rapidly reduced, which draws enough attention in construction, and the adverse effect on the foundation caused by the residual soil and the completely weathered argillaceous siltstone in design and construction needs to be paid attention to.

The engineering adopts a pretensioning method to prestress high-strength concrete pipe piles (PC piles), the diameter of each pile is 400mm, the average length of each pile with the wall thickness of 95mm is 15m, and the total number of the piles is 50.

The construction method of the tubular pile foundation for the sediment treatment plant comprises the following steps:

(1) leveling the field: cleaning various wastes in a pile foundation area, backfilling a foundation to a designed elevation, carrying out earth balance, and leveling a field to meet the pile foundation construction requirement;

(2) and (3) field paying-off: arranging a plurality of pile pre-leveling points near a piling construction area, wherein axis control is arranged 7-8m away from an outer pile to control the axis and elevation of the pile; placing the positioning line of the pile according to the drawing, and pressing outwards from the center to form the pile so as to prevent hole leakage and dislocation; according to the known control points on site, pile position control points are measured and released according to the pile spacing required by design; the pile position measurement and positioning are carried out by adopting theodolite orientation and steel ruler distance measurement;

(3) preparing a piling device: moving the pile driver to the pile position according to the pile driving sequence, aligning the pile position, adjusting the pile driver to be horizontal and stable, and avoiding inclination and movement in construction;

(4) piling: transporting the pipe piles to the site by using a flat car, unloading the pipe piles to one side of a pile machine by using a crane, and stacking the pipe piles according to the piling sequence and the matching requirements of the piles; when the tubular pile is hung to a pile position, the tubular pile is hung to a pile machine clamp and aligned to the pile position, the tubular pile is clamped and placed into the soil, the pile machine is moved to adjust the verticality of the pile, the pile tip is placed into the soil, then the pile machine is adjusted to be horizontal and stable, then the lifting appliance is removed to insert the pile, and the pile tip is pressed into the soil by means of the dead weight and the balance weight of the tubular pile; in the process, the pressure does not exceed the strength of the pile body, and the center lines of the pile cap, the pile body and the pile feeding are coincided; then piling, correcting the verticality of the pile frame guide rod and the pile during piling, and keeping the hammer, the pile tip and the pile on the same longitudinal axis; during pile driving, the pile needs to be driven and welded to be lengthened while the pile is driven, an alternating current welding machine is adopted for welding, groove welding is adopted for pipe pile welding, a lining hoop is placed on a stop block on the inner side of a lower pile section, the inner wall of the pipe pile is tightly attached to the stop block for sectional spot welding, then the upper pile section is hung, a groove is placed on a welding bead, the upper pile section and the lower pile section are kept straight, the dislocation deviation is 0.5-1mm, the verticality is corrected by using a theodolite, and then spot welding; welding is symmetrically carried out, multilayer welding is applied, the welding seam joints of all layers of the tubular pile are staggered, and welding slag is removed from each layer;

(5) pile cutting treatment: arranging a core-pulling machine frame above the tubular pile, and cutting the tubular pile into rings by using a cutting machine without damaging a steel bar framework in the tubular pile during cutting; installing core-pulling equipment on the core-pulling machine, drilling and stripping concrete of the tubular pile through the core-pulling equipment; removing residual concrete on the tubular pile to expose the steel reinforcement framework;

(6) and (6) checking and accepting.

The method comprises the following steps of firstly testing the pile before the construction of the pipe pile foundation, and specifically comprises the following steps: excavating a foundation pit at a selected position of a selected site; sinking a design pipe pile into a bearing layer of a soil body in the foundation pit, and enabling a gap to be formed between the foundation pit and the pile side of the design pipe pile positioned in the foundation pit; and filling crushed stone with the particle size of 5-6mm in the gap until the crushed stone surrounds the pile side of the designed tubular pile.

When the design pile is a tubular pile, the diameter of the positioning pit is larger than 150-200mm of the diameter of the tubular pile.

In the step (2), the distance between the pre-leveling points of the plurality of control piles and the piling construction area is 45-50m, and after the pile position control points are measured and released, the holes are punched by steel drill rods and marked by pouring lime.

And (4) hoisting the pile by adopting one-point binding, bidirectionally correcting the verticality after the pipe pile is in place, stopping piling and timely correcting when the verticality deviation exceeds 0.5 percent of the length of a single pile, ensuring the verticality of the pile body, and controlling the elevation by using a GPS (global positioning system) so as to ensure that the elevation of the pile top is consistent with the designed elevation.

In the step (4), after the pile tip of the tubular pile is inserted into the pile position, the verticality deviation of the pile is 0.2-0.3% when the pile driver is moved, the pile top allowable deviation is +/-30 mm, and the pile driver is in a stable state; the hammer is low-impact when the piling is started, and the height of the falling hammer from the falling hammer is 0.3-0.4 m; each pile is continuously driven once, the two hanging hammers form a 90-degree direction for observation from the front and the side in the piling process, the verticality of the pile is ensured in the piling process, and the deviation of the pile top is controlled to be 2-3 cm.

In the step (4), pile splicing is carried out when the pile is jacked to be 70-80cm away from the ground, the pile is spliced when the pile tip is prevented from approaching a hard holding layer or is positioned in the middle of the hard holding layer, welding is adopted for pile splicing, water, oil, rust or other dirt in a groove is removed before welding, and anti-rust paint is brushed; when pile splicing is carried out, the periphery is fixed by spot welding and then is symmetrically welded, the deviation of the central lines of the upper pile section and the lower pile section is 4-6mm, and the bending vector of the node is not more than 1% of the pile length.

In the step (5), when pile cutting is not needed, connecting the pile top of the pile without pile cutting with the bearing platform by arranging a first end plate at one end of the pipe pile, arranging a connecting piece on the end plate, welding a connecting rib on the connecting piece, arranging one end part of the end plate on the pipe pile, positioning the connecting rib in the bearing platform, arranging a second end plate at the other end of the pipe pile, arranging an anchoring reinforcing steel bar inside the second end plate, and arranging concrete between the anchoring reinforcing steel bar and the second end plate; the connecting ribs and the anchoring reinforcing steel bars are uniformly distributed along the circumferential direction of the tubular pile respectively, and the length of the connecting ribs welded with the connecting pieces is 1/2-3/4 of the diameter of the connecting ribs; and two ends of the anchoring reinforcing steel bar are respectively connected with the first end plate and the second end plate in a welding mode.

Example 2

A construction method of a tubular pile foundation for a sediment disposal plant comprises the following steps:

(1) leveling the field: cleaning various wastes in a pile foundation area, backfilling a foundation to a designed elevation, carrying out earth balance, and leveling a field to meet the pile foundation construction requirement;

(2) and (3) field paying-off: arranging a plurality of pile pre-leveling points near a piling construction area, wherein axis control is arranged 7-8m away from an outer pile to control the axis and elevation of the pile; placing the positioning line of the pile according to the drawing, and pressing outwards from the center to form the pile so as to prevent hole leakage and dislocation; according to the known control points on site, pile position control points are measured and released according to the pile spacing required by design; the pile position measurement and positioning are carried out by adopting theodolite orientation and steel ruler distance measurement;

(3) preparing a piling device: moving the pile driver to the pile position according to the pile driving sequence, aligning the pile position, adjusting the pile driver to be horizontal and stable, and avoiding inclination and movement in construction;

(4) piling: transporting the pipe piles to the site by using a flat car, unloading the pipe piles to one side of a pile machine by using a crane, and stacking the pipe piles according to the piling sequence and the matching requirements of the piles; when the tubular pile is hung to a pile position, the tubular pile is hung to a pile machine clamp and aligned to the pile position, the tubular pile is clamped and placed into the soil, the pile machine is moved to adjust the verticality of the pile, the pile tip is placed into the soil, then the pile machine is adjusted to be horizontal and stable, then the lifting appliance is removed to insert the pile, and the pile tip is pressed into the soil by means of the dead weight and the balance weight of the tubular pile; in the process, the pressure does not exceed the strength of the pile body, and the center lines of the pile cap, the pile body and the pile feeding are coincided; then piling, correcting the verticality of the pile frame guide rod and the pile during piling, and keeping the hammer, the pile tip and the pile on the same longitudinal axis; during pile driving, the pile needs to be driven and welded to be lengthened while the pile is driven, an alternating current welding machine is adopted for welding, groove welding is adopted for pipe pile welding, a lining hoop is placed on a stop block on the inner side of a lower pile section, the inner wall of the pipe pile is tightly attached to the stop block for sectional spot welding, then the upper pile section is hung, a groove is placed on a welding bead, the upper pile section and the lower pile section are kept straight, the dislocation deviation is 0.5-1mm, the verticality is corrected by using a theodolite, and then spot welding; welding is symmetrically carried out, multilayer welding is applied, the welding seam joints of all layers of the tubular pile are staggered, and welding slag is removed from each layer;

(5) pile cutting treatment: arranging a core-pulling machine frame above the tubular pile, and cutting the tubular pile into rings by using a cutting machine without damaging a steel bar framework in the tubular pile during cutting; installing core-pulling equipment on the core-pulling machine, drilling and stripping concrete of the tubular pile through the core-pulling equipment; removing residual concrete on the tubular pile to expose the steel reinforcement framework;

(6) and (6) checking and accepting.

The method comprises the following steps of firstly testing the pile before the construction of the pipe pile foundation, and specifically comprises the following steps: excavating a foundation pit at a selected position of a selected site; sinking a design pipe pile into a bearing layer of a soil body in the foundation pit, and enabling a gap to be formed between the foundation pit and the pile side of the design pipe pile positioned in the foundation pit; and filling crushed stone with the particle size of 5-6mm in the gap until the crushed stone surrounds the pile side of the designed tubular pile.

When the design pile is a tubular pile, the diameter of the positioning pit is larger than 150-200mm of the diameter of the tubular pile.

In the step (2), the distance between the pre-leveling points of the plurality of control piles and the piling construction area is 45-50m, and after the pile position control points are measured and released, the holes are punched by steel drill rods and marked by pouring lime.

And (4) hoisting the pile by adopting one-point binding, bidirectionally correcting the verticality after the pipe pile is in place, stopping piling and timely correcting when the verticality deviation exceeds 0.5 percent of the length of a single pile, ensuring the verticality of the pile body, and controlling the elevation by using a GPS (global positioning system) so as to ensure that the elevation of the pile top is consistent with the designed elevation.

In the step (4), after the pile tip of the tubular pile is inserted into the pile position, the verticality deviation of the pile is 0.2-0.3% when the pile driver is moved, the pile top allowable deviation is +/-30 mm, and the pile driver is in a stable state; the hammer is low-impact when the piling is started, and the height of the falling hammer from the falling hammer is 0.3-0.4 m; each pile is continuously driven once, the two hanging hammers form a 90-degree direction for observation from the front and the side in the piling process, the verticality of the pile is ensured in the piling process, and the deviation of the pile top is controlled to be 2-3 cm.

In the step (4), pile splicing is carried out when the pile is jacked to be 70-80cm away from the ground, the pile is spliced when the pile tip is prevented from approaching a hard holding layer or is positioned in the middle of the hard holding layer, welding is adopted for pile splicing, water, oil, rust or other dirt in a groove is removed before welding, and anti-rust paint is brushed; when pile splicing is carried out, the periphery is fixed by spot welding and then is symmetrically welded, the deviation of the central lines of the upper pile section and the lower pile section is 4-6mm, and the bending vector of the node is not more than 1% of the pile length.

In the step (5), when pile cutting is not needed, connecting the pile top of the pile without pile cutting with the bearing platform by arranging a first end plate at one end of the pipe pile, arranging a connecting piece on the end plate, welding a connecting rib on the connecting piece, arranging one end part of the end plate on the pipe pile, positioning the connecting rib in the bearing platform, arranging a second end plate at the other end of the pipe pile, arranging an anchoring reinforcing steel bar inside the second end plate, and arranging concrete between the anchoring reinforcing steel bar and the second end plate; the connecting ribs and the anchoring reinforcing steel bars are uniformly distributed along the circumferential direction of the tubular pile respectively, and the length of the connecting ribs welded with the connecting pieces is 1/2-3/4 of the diameter of the connecting ribs; and two ends of the anchoring reinforcing steel bar are respectively connected with the first end plate and the second end plate in a welding mode.

In addition, pile driver process accomplishes the back, if the straightness that hangs down of tubular pile has the deviation, then adopt following step to correct the straightness that hangs down:

1. tubular pile perpendicularity detection

2. Determination of integrity of tubular pile body

Carrying out small strain detection on the tubular pile to judge the integrity of the pile body of the tubular pile or whether the pile body of the tubular pile has quality defects; for the tubular pile with the quality defect on the pile body, the defect needs to be repaired first, and then the correction procedure is allowed to be continuously implemented;

3. setting a tubular pile position correcting route;

4. paying off according to a tubular pile position correcting route, reserving an inclined tubular pile to correct a regression hole: the length is 500-800mm, and the width is 2 times of the pile diameter;

5. stress release hole

Drilling a plurality of stress release holes in the regression holes according to the correction route; for the pipe pile with the complete pile body, the drilling depth is 1m-2m below the soft soil layer; for the tubular pile with the quality defect of the pile body, the drilling depth is 3m-5m below the defect part of the tubular pile;

6. setting anchoring points

Correcting the direction of the route at the pile position of the tubular pile, and fixing the excavator outside the foundation pit as a field anchoring point;

7. setting supporting points

Welding a support base body on a reinforcing steel bar ring at the periphery of the regression hole as a field support point in the reverse direction of the tubular pile position correction route;

8. implement deviation rectification

Arranging a hand-operated block and a steel wire rope between a tubular pile head and an excavator, arranging a jack between the tubular pile head and a support seat body, and adopting an intermittent multiple-application method to enable the tubular pile to gradually return to a designed pile position from an actual pile position of the tubular pile;

9. detecting the verticality;

10. tubular pile deviation rectifying quality detection

After the deviation of the tubular pile is corrected, small strain detection is required again, after the deviation is qualified, compression resistance and pull resistance tests are required to be carried out according to the using function of the engineering pile, and after the deviation is qualified, the subsequent procedures can be carried out.

The method can effectively solve the problem that the tubular pile needs to adopt deviation correction or pile foundation reinforcement measures after judgment in the concrete tubular pile foundation construction, so that the tubular pile with the out-of-plumb degree and the pile body with quality defects is reset, the bearing capacity requirement of the foundation design on the tubular pile is met, and the method has the advantages of simple process, strong practicability and good deviation correction effect.

Example 3

A construction method of a tubular pile foundation for a sediment disposal plant comprises the following steps:

(1) leveling the field: cleaning various wastes in a pile foundation area, backfilling a foundation to a designed elevation, carrying out earth balance, and leveling a field to meet the pile foundation construction requirement;

(2) and (3) field paying-off: arranging a plurality of pile pre-leveling points near a piling construction area, wherein axis control is arranged 7-8m away from an outer pile to control the axis and elevation of the pile; placing the positioning line of the pile according to the drawing, and pressing outwards from the center to form the pile so as to prevent hole leakage and dislocation; according to the known control points on site, pile position control points are measured and released according to the pile spacing required by design; the pile position measurement and positioning are carried out by adopting theodolite orientation and steel ruler distance measurement;

(3) preparing a piling device: moving the pile driver to the pile position according to the pile driving sequence, aligning the pile position, adjusting the pile driver to be horizontal and stable, and avoiding inclination and movement in construction;

(4) piling: transporting the pipe piles to the site by using a flat car, unloading the pipe piles to one side of a pile machine by using a crane, and stacking the pipe piles according to the piling sequence and the matching requirements of the piles; when the tubular pile is hung to a pile position, the tubular pile is hung to a pile machine clamp and aligned to the pile position, the tubular pile is clamped and placed into the soil, the pile machine is moved to adjust the verticality of the pile, the pile tip is placed into the soil, then the pile machine is adjusted to be horizontal and stable, then the lifting appliance is removed to insert the pile, and the pile tip is pressed into the soil by means of the dead weight and the balance weight of the tubular pile; in the process, the pressure does not exceed the strength of the pile body, and the center lines of the pile cap, the pile body and the pile feeding are coincided; then piling, correcting the verticality of the pile frame guide rod and the pile during piling, and keeping the hammer, the pile tip and the pile on the same longitudinal axis; during pile driving, the pile needs to be driven and welded to be lengthened while the pile is driven, an alternating current welding machine is adopted for welding, groove welding is adopted for pipe pile welding, a lining hoop is placed on a stop block on the inner side of a lower pile section, the inner wall of the pipe pile is tightly attached to the stop block for sectional spot welding, then the upper pile section is hung, a groove is placed on a welding bead, the upper pile section and the lower pile section are kept straight, the dislocation deviation is 0.5-1mm, the verticality is corrected by using a theodolite, and then spot welding; welding is symmetrically carried out, multilayer welding is applied, the welding seam joints of all layers of the tubular pile are staggered, and welding slag is removed from each layer;

(5) pile cutting treatment: arranging a core-pulling machine frame above the tubular pile, and cutting the tubular pile into rings by using a cutting machine without damaging a steel bar framework in the tubular pile during cutting; installing core-pulling equipment on the core-pulling machine, drilling and stripping concrete of the tubular pile through the core-pulling equipment; removing residual concrete on the tubular pile to expose the steel reinforcement framework;

(6) and (6) checking and accepting.

The method comprises the following steps of firstly testing the pile before the construction of the pipe pile foundation, and specifically comprises the following steps: excavating a foundation pit at a selected position of a selected site; sinking a design pipe pile into a bearing layer of a soil body in the foundation pit, and enabling a gap to be formed between the foundation pit and the pile side of the design pipe pile positioned in the foundation pit; and filling crushed stone with the particle size of 5-6mm in the gap until the crushed stone surrounds the pile side of the designed tubular pile.

When the design pile is a tubular pile, the diameter of the positioning pit is larger than 150-200mm of the diameter of the tubular pile.

In the step (2), the distance between the pre-leveling points of the plurality of control piles and the piling construction area is 45-50m, and after the pile position control points are measured and released, the holes are punched by steel drill rods and marked by pouring lime.

And (4) hoisting the pile by adopting one-point binding, bidirectionally correcting the verticality after the pipe pile is in place, stopping piling and timely correcting when the verticality deviation exceeds 0.5 percent of the length of a single pile, ensuring the verticality of the pile body, and controlling the elevation by using a GPS (global positioning system) so as to ensure that the elevation of the pile top is consistent with the designed elevation.

In the step (4), after the pile tip of the tubular pile is inserted into the pile position, the verticality deviation of the pile is 0.2-0.3% when the pile driver is moved, the pile top allowable deviation is +/-30 mm, and the pile driver is in a stable state; the hammer is low-impact when the piling is started, and the height of the falling hammer from the falling hammer is 0.3-0.4 m; each pile is continuously driven once, the two hanging hammers form a 90-degree direction for observation from the front and the side in the piling process, the verticality of the pile is ensured in the piling process, and the deviation of the pile top is controlled to be 2-3 cm.

In the step (4), pile splicing is carried out when the pile is jacked to be 70-80cm away from the ground, the pile is spliced when the pile tip is prevented from approaching a hard holding layer or is positioned in the middle of the hard holding layer, welding is adopted for pile splicing, water, oil, rust or other dirt in a groove is removed before welding, and anti-rust paint is brushed; when pile splicing is carried out, the periphery is fixed by spot welding and then is symmetrically welded, the deviation of the central lines of the upper pile section and the lower pile section is 4-6mm, and the bending vector of the node is not more than 1% of the pile length.

In the step (5), when pile cutting is not needed, connecting the pile top of the pile without pile cutting with the bearing platform by arranging a first end plate at one end of the pipe pile, arranging a connecting piece on the end plate, welding a connecting rib on the connecting piece, arranging one end part of the end plate on the pipe pile, positioning the connecting rib in the bearing platform, arranging a second end plate at the other end of the pipe pile, arranging an anchoring reinforcing steel bar inside the second end plate, and arranging concrete between the anchoring reinforcing steel bar and the second end plate; the connecting ribs and the anchoring reinforcing steel bars are uniformly distributed along the circumferential direction of the tubular pile respectively, and the length of the connecting ribs welded with the connecting pieces is 1/2-3/4 of the diameter of the connecting ribs; and two ends of the anchoring reinforcing steel bar are respectively connected with the first end plate and the second end plate in a welding mode.

In addition, the pile extension construction method of the tubular pile comprises the following construction steps:

(1) removing mud around the pile body of the tubular pile, and chiseling the pile body at the position above the fracture;

(2) arranging a reinforcement cage with prestress higher than that of the steel bar in the pipe pile by one grade in the pile broken hole, wherein the top of the reinforcement cage reaches the elevation of the design requirement; if the distance from the pile body fracture part to the ground is not more than 2m, the distance from the bottom of the reinforcement cage to the pile opening of the broken pile is 1-1.1m, simultaneously excavating the soil around the pile body in a cuboid shape to be 30-35cm below the pile fracture part, placing templates around the cuboid soil wall, wherein the side length of each template is larger than the outer diameter of the broken pile by 110 plus 130mm, the top of each template reaches the elevation required by design, and pouring concrete into the templates placed around the cuboid soil wall to the top of each template; if the distance from the pile body fracture position to the ground is larger than 2m, the distance from the bottom of the reinforcement cage to the pile opening of the broken pile is 2.1-2.2m, and grouting material is poured into the reinforcement cage with the distance from the pile body fracture position to the ground larger than 2m to the top of the reinforcement cage; the poured concrete is C70 concrete, and the poured grouting material is H90 grouting material;

(3) curing for 10-12 days until the strength meets the requirement.

The method effectively utilizes the underground broken pile, saves materials and reduces the construction cost of foundation engineering. The operation is simple, the piling is avoided, and the construction period is shortened and prolonged.

Quality control:

1. the verticality of the pile body is visually measured before the pipe pile is inserted and drilled, and the surface flatness is measured by a 2m guiding rule and cannot exceed 10 mm.

2. The deviation of the central line of the pile at the upper section and the lower section is 4-6mm, the bending vector of the node is not more than 1% of the pile length and is less than or equal to 20 mm.

3. The distance between piles is ensured, the horizontal deviation and the longitudinal deviation are less than or equal to 50mm, the verticality deviation of the piles is not more than 0.5 percent of the length of the piles, and the number of the piles is not less than 5.

In addition, in order to achieve better technical effects, the technical solutions in the above embodiments may be combined arbitrarily to meet various requirements of practical applications.

The embodiment shows that the method can be effectively used for construction requirements of the bottom mud treatment plant, and solves the problems of safety and stability of the bottom mud treatment plant.

Because the thickness and the particle size of the filled crushed stone are known, the frictional resistance characteristic value of the pile side of the designed tubular pile can be determined, the vertical bearing capacity characteristic value of the pile can be accurately calculated, the accuracy of pile testing is improved, the safety and the quality of a building structure are guaranteed, the construction cost of a project is reduced, and the construction period is shortened.

The construction method of the invention improves the construction quality of pile foundation engineering, ensures the safety and stability of buildings, effectively improves the construction efficiency, shortens the construction period and reduces the construction cost.

The invention has simple operation, labor saving, error rate reduction and convenient construction.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.