阅读说明：本技术 用于填海软弱地层的支盘桩及其施工方法 (Supporting disk pile for filling soft stratum and construction method thereof ) 是由 肖友银 汪波 施劭矗 马龙祥 姬繁 戴文 沈道旭 刘厚朴 于 2021-06-28 设计创作，主要内容包括：本发明公开了用于填海软弱地层的支盘桩及其施工方法,施工方法包括场地平整、测量放样；埋设钢护筒、钻机就位、钻进施工；终孔检查；第一次清孔及测孔；挤扩支盘成型；扫孔；第二次清孔及测孔；安放钢筋笼、吊放导管；第三次清孔；灌注水下砼；高压注浆；本施工方法通过三次清孔及超声波成孔检测仪与井径仪双重检测的方式,并在施工过程中选用优质泥浆,确保了支盘桩成桩质量,解决了复杂填海软弱地层,尤其是上覆深厚软土地区的支盘桩施工难题,施工成本低、安全可靠。(The invention discloses a support pile for filling a soft stratum in the sea and a construction method thereof, wherein the construction method comprises the steps of leveling a field, measuring and lofting; embedding a steel casing, positioning a drilling machine and performing drilling construction; inspecting a final hole; cleaning and measuring holes for the first time; forming a squeezing and expanding branch disc; hole sweeping; cleaning and measuring the hole for the second time; placing a steel reinforcement cage and a hanging guide pipe; cleaning the hole for the third time; pouring underwater concrete; high-pressure grouting; the construction method ensures the pile forming quality of the branch pile by adopting a mode of three-time hole cleaning and double detection of the ultrasonic pore-forming detector and the caliper and selecting high-quality slurry in the construction process, solves the construction problem of the branch pile in a complex sea-filling soft stratum, particularly in a region covered with deep soft soil, and has low construction cost, safety and reliability.)

1. A supporting disk pile for filling a weak stratum in the sea comprises:

drilling a pile body of the cast-in-place pile;

a plurality of extruded branch tray structures; the multiple squeezing and expanding support disc structures are respectively arranged around multiple axial positions of the cast-in-situ bored pile body;

the branch disk pile for filling the sea soft stratum is characterized by further comprising:

a soil body reinforcing disc structure; the soil body reinforcing plate structure is arranged on the silt layer, the soil body reinforcing plate structure is arranged around a pile body of the cast-in-situ bored pile, and the soil body reinforcing plate structure is formed by soft soil and cement mortar.

2. The construction method of the branch pile for filling the weak stratum in the sea is characterized by comprising the following steps:

s01; leveling a field, and measuring and lofting; positioning the center of the pile position;

s02; embedding a steel casing, positioning a drilling machine and performing drilling construction; the center of a drill bit of the drilling machine and the center of the pile casing are positioned on the same plumb line, and then drilling is started from the center of the positioning pile position until the target hole depth is reached;

s03; inspecting a final hole; measuring the hole depth;

s04; cleaning and measuring holes for the first time; removing sediments such as slurry on the wall of the casing, drilling slag on the bottom of the hole and silt; and detecting the performance of slurry in the hole, the verticality of the hole, the depth of the hole and the aperture;

s05; forming a squeezing and expanding branch disc; lifting a drill bit of the drilling machine, lowering the squeezing and expanding equipment into the hole, and squeezing and expanding the pile supporting disc part for forming;

s06; hole sweeping; after the squeezing and expanding are finished, lifting the squeezing and expanding equipment, lowering a drill bit of a drilling machine to sweep the hole, and stopping when the designed hole depth is reached;

s07; cleaning and measuring the hole for the second time; removing sediments such as slurry on the wall of the casing, drilling slag on the bottom of the hole and silt;

s08; placing a steel reinforcement cage and a hanging guide pipe; hoisting the reinforcement cage and the guide pipe to the bottom of the hole;

s09; cleaning the hole for the third time; until the quality of the slurry at the bottom of the hole meets the requirement;

s10; pouring underwater concrete; pouring underwater concrete until a pile body of the cast-in-situ bored pile and a plurality of extruding and expanding support disc structures are formed;

s11; high-pressure grouting; and (4) injecting clear water into the high pressure to open a hole, and injecting prepared cement mortar to split and reinforce the soft soil into a plate.

3. The method for constructing a branch pile for filling a weak sea formation according to claim 2, wherein the step S01 includes: and ensuring that no sundries exist in the pile foundation construction range of 5 meters, compacting the ground by a road roller, accurately positioning the pile position center by using a total station, and measuring and placing a cross lead.

4. The method for constructing a branch pile for filling a weak stratum in the sea according to claim 2, wherein in step S02, the top of the pile casing is installed to be 30cm higher than the ground, and the bottom of the steel pile casing is located 2-3 m below the ground.

5. The method of constructing a branch pile for use in reclamation of a weak sea formation according to claim 2, wherein the drilling machine is a light-weight slow drilling machine during the hole opening, and the pressure and the speed are gradually increased with the increase of the depth in step S02; the thick mud is adopted to protect the wall of the loose soil, and the drilling speed is slowed down.

6. The construction method of a branch pile for filling a weak stratum in the sea according to claim 2, wherein in step S04, the specific gravity of the mud at the bottom of the hole after the first hole cleaning is 1.15-1.20, the sand content is less than 2%, and the thickness of the sediment at the bottom of the hole is less than 50 cm.

7. The construction method of a branch pile for filling a weak stratum in the sea according to claim 2, wherein in step S07, the specific gravity of the mud at the bottom of the hole after the second hole cleaning is 1.15-1.20, the sand content is less than 2%, and the thickness of the sediment at the bottom of the hole is less than 15 cm.

8. The construction method of a branch pile for filling a weak stratum in the sea according to claim 2, wherein in step S9, the specific gravity of the mud at the bottom of the hole after the third hole cleaning is 1.10-1.15, the sand content is less than 2%, and the thickness of the sediment at the bottom of the hole is less than 15 cm.

9. The method of constructing a branch pile for use in filling a weak sea formation according to claim 2, wherein the diameter of the squeezed branch structure is greater than 0.95 times the design diameter in sandy soil and greater than 0.9 times the design diameter in cohesive soil in step S10.

10. The construction method of the branch pile for filling the weak stratum in the sea as claimed in claim 2, wherein the construction of the squeezed branch structure selects at least two mud mixture ratios, the mud specific gravity is controlled to be 1.05-1.2 under the general stratum, and the mud specific gravity is increased to 1.2-1.3 when the mud passes through the stratum with easy hole collapse.

Technical Field

The invention relates to the technical field of branch pile, in particular to a branch pile for filling a sea soft stratum and a construction method thereof.

Background

The offshore filling stratum is more complex in distribution and poorer in physical and mechanical properties than the common rock-soil body, and is influenced by the sea environment, and the physical and mechanical properties of the offshore filling stratum are possibly worse, so that the reinforcement means of the foundation of the sea filling stratum is particularly important.

The extruding and expanding branch disk pile is a special-shaped pile designed and researched by combining the shape of a variable cross-section bored pile according to the compression and pulling resistance mechanism of a tree root, the branch disk not only increases the side surface area of the pile, but also can fully utilize the end bearing capacity of each soil layer so as to greatly improve the bearing capacity of a single pile, the settlement is small after the pile is formed, and therefore, the branch disk pile is adopted to carry out foundation reinforcement to become a hot choice. However, the sea-filling stratum has a thick soft soil layer, the pile foundation is difficult to form holes, the sediment is thick, and the bearing capacity of the pile foundation after pile forming often cannot meet the requirement. Therefore, how to apply the novel support disk pile in the sea-filling stratum and ensure the construction quality is a difficult problem to be solved urgently.

Therefore, it is necessary to develop a branch pile for filling a weak stratum in the sea and a construction method thereof to solve the above problems.

Disclosure of Invention

The invention aims to solve the problems and designs a supporting disk pile for filling a sea weak stratum and a construction method thereof.

The invention realizes the purpose through the following technical scheme:

a supporting disk pile for filling a weak stratum in the sea comprises:

drilling a pile body of the cast-in-place pile;

a plurality of extruded branch tray structures; the multiple squeezing-expanding support disc structures are respectively arranged around multiple axial positions of the cast-in-situ bored pile body;

a soil body reinforcing disc structure; the soil body reinforcing plate structure is arranged on the silt layer, the soil body reinforcing plate structure is arranged around the pile body of the cast-in-place bored pile, and the soil body reinforcing plate structure is formed by soft soil and cement mortar.

The construction method of the branch pile for filling the weak stratum in the sea comprises the following steps:

s01; leveling a field, and measuring and lofting; positioning the center of the pile position;

s02; embedding a steel casing, positioning a drilling machine and performing drilling construction; the center of a drill bit of the drilling machine and the center of the pile casing are positioned on the same plumb line, and then drilling is started from the center of the positioning pile position until the target hole depth is reached;

s03; inspecting a final hole; measuring the hole depth;

s04; cleaning and measuring holes for the first time; removing sediments such as slurry on the wall of the casing, drilling slag on the bottom of the hole and silt; and detecting the performance of slurry in the hole, the verticality of the hole, the depth of the hole and the aperture;

s05; forming a squeezing and expanding branch disc; lifting a drill bit of the drilling machine, lowering the squeezing and expanding equipment into the hole, and squeezing and expanding the pile supporting disc part for forming;

s06; hole sweeping; after the squeezing and expanding are finished, lifting the squeezing and expanding equipment, lowering a drill bit of a drilling machine to sweep the hole, and stopping when the designed hole depth is reached;

s07; cleaning and measuring the hole for the second time; removing sediments such as slurry on the wall of the casing, drilling slag on the bottom of the hole and silt;

s08; placing a steel reinforcement cage and a hanging guide pipe; hoisting the reinforcement cage and the guide pipe to the bottom of the hole;

s09; cleaning the hole for the third time; until the quality of the slurry at the bottom of the hole meets the requirement;

s10; pouring underwater concrete; pouring underwater concrete until a pile body of the cast-in-situ bored pile and a plurality of extruding and expanding support disc structures are formed;

s11; high-pressure grouting; and (4) injecting clear water at high pressure to open a hole, and injecting prepared cement mortar to split and reinforce the soft soil into a plate.

The soft soil layer is reinforced by adopting a high-pressure splitting grouting mode, the bearing capacity of the soft soil layer foundation is fully improved, and a favorable guarantee is provided for pile foundation stress.

Specifically, step S01 includes: and ensuring that no sundries exist in the pile foundation construction range of 5 meters, compacting the field by the road roller, accurately positioning the pile position center by using a total station, and measuring and placing the cross lead.

Specifically, in step S02, the top of the pile casing is arranged to be 30cm higher than the ground, and the bottom of the steel pile casing is arranged 2-3 m below the ground.

Specifically, in step S02, the drilling machine is a light-pressure slow drill during drilling, and the pressure and speed are gradually increased along with the increase of the depth; the thick mud is adopted to protect the wall of the loose soil, and the drilling speed is slowed down.

Specifically, in step S04, the specific gravity of the bottom-hole slurry after the first hole cleaning is 1.15-1.20, the sand content is less than 2%, and the thickness of the bottom-hole sediment is less than 50 cm.

Specifically, in step S07, the specific gravity of the hole bottom slurry after the second hole cleaning is 1.15-1.20, the sand content is less than 2%, and the thickness of the hole bottom sediment is less than 15 cm.

Specifically, in step S9, the specific gravity of the bottom-hole slurry after the third hole cleaning should be 1.10-1.15, the sand content is less than 2%, and the thickness of the bottom-hole sediment is less than 15 cm.

Specifically, in step S10, the diameter of the squeeze-expansion tray structure is greater than 0.95 times the design diameter in sandy soil and greater than 0.9 times the design diameter in cohesive soil.

Specifically, at least two slurry mixing ratios are selected for construction of the squeezing and expanding support disc structure, the specific gravity of the slurry is controlled to be 1.05-1.2 under a common stratum, and the specific gravity of the slurry is increased to 1.2-1.3 when the slurry passes through a stratum with easy hole collapse.

The invention has the beneficial effects that:

1. the invention adopts a three-time hole cleaning mode, the pile forming quality of the supporting disk pile is high, and the excessive thickness of sediments and the situation that the diameter of the supporting disk does not meet the design requirements can be effectively avoided.

2. The invention utilizes the soil body reinforcing disc structure formed by extruding and expanding the supporting disc structure and high-pressure splitting soft soil, fully increases the end bearing effect of the pile foundation, and has high bearing capacity and small deformation.

3. The invention selects two slurry mixing ratios, and solves the problems of difficult hole forming and easy hole collapse of the pile foundation in the sea-filling stratum.

Drawings

FIG. 1 is a schematic diagram of a prior art configuration;

FIG. 2 is a schematic structural diagram of the present application;

wherein, 1-locking long rod; 2-a locking bush; 3-an upstream connecting pipe flange; 4-locking the short bar; 5, overhauling and sealing; 6-ball valve end cover; 7-ball valve body.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, 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. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. The components of embodiments of the present invention, generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. 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.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "inside", "outside", "left", "right", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, or the orientations or positional relationships that the products of the present invention are conventionally placed in use, or the orientations or positional relationships that are conventionally understood by those skilled in the art, and are used for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element being referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is also to be noted that, unless otherwise explicitly stated or limited, the terms "disposed" and "connected" are to be interpreted broadly, for example, "connected" may be a fixed connection, a detachable connection, or an integral connection; can be mechanically or electrically connected; the connection may be direct or indirect via an intermediate medium, and may be a communication between the two elements. Specific meanings of the above terms in the present invention can be understood by those of ordinary skill in the art as appropriate.

The following detailed description of embodiments of the invention refers to the accompanying drawings.

As shown in fig. 1, the invention provides a support disc pile for filling a weak stratum in the sea, which comprises a bored pile body, a plurality of squeezing and expanding support disc structures 7 and a soil body reinforcing disc structure 6; the multiple squeezing-expanding support disc structures 7 are respectively arranged around multiple axial positions of the cast-in-situ bored pile body; the soil body reinforcing plate structure 6 is arranged on the silt layer 2, the soil body reinforcing plate structure 6 is arranged around a pile body of the cast-in-situ bored pile, and the soil body reinforcing plate structure 6 is formed by soft soil and cement mortar.

The description is given here in connection with the engineering practice of the soil layer: the engineering sea-filling stratum comprises an artificial filling soil layer 1, a silt layer 2, a gravel viscous soil layer 3, a cohesive soil-containing gravel layer 4 and a completely weathered granite stratum 5, wherein the silt layer is a softer and weak stratum. The bored concrete pile body includes traditional bored concrete pile body concrete 8 and is located the steel reinforcement cage 9 of pile body, is provided with high-pressure slip casting pipe 10 on the steel reinforcement cage top, and high-pressure slip casting pipe 10 external high-pressure slip casting equipment.

The invention provides a construction method of a support pile for filling a soft stratum in the sea, which is mainly used for solving the problem of insufficient bearing capacity of a pile foundation caused by excessive thickness of mud skin and sediment in a deep and thick soft soil covering layer area in the coastal region by adopting a traditional cast-in-place pile.

As shown in fig. 2, the construction method includes the following steps:

s01: leveling the field, and measuring and lofting;

and (3) cleaning a construction site, ensuring that no sundries exist in the pile foundation construction range within 5 meters, compacting the site by a road roller, and ensuring the stability of the construction process of a drilling machine. And (4) accurately positioning the pile position center by using a total station, and measuring and placing the cross lead.

S02: embedding a steel casing, positioning a drilling machine, and performing drilling construction;

embedding a steel casing, preparing sufficient slurry, enabling the center of a drill bit of the drilling machine and the center of the casing to be located on the same plumb line, and starting drilling after ensuring that the deviation between the drill bit and the center of a hole site is within a standard allowable range.

When the hole is opened, the drilling machine is slightly pressed and slowly rotated, the pressure and the speed are properly increased along with the increase of the depth, the wall is protected by thick slurry when the soil loose layer is formed, the drilling speed and the rotating speed are reduced, and the hole collapse is prevented by slightly drilling and slowly advancing.

And (3) setting up at least two slurry mixing ratios in the construction of the branch pile. The specific gravity of the slurry is controlled to be 1.05-1.2 under the general condition, and the specific gravity of the slurry is increased to 1.2-1.3 when the slurry passes through the stratum with the easy-collapse hole.

S03: inspecting a final hole;

and when the drilling is close to the designed hole depth of the pile, measuring the hole depth by using a measuring rope, slowing down the drilling speed until the pile hole depth is reached, stopping the drilling when the designed hole depth is reached, and checking the hole depth by using a measuring hammer with the weight not less than 5 KG.

S04: cleaning and measuring holes for the first time;

and after the final hole is finished, cleaning the hole for the first time, cleaning the slurry attached to the wall of the protective cylinder, and removing sediments such as drilling slag, silt and the like at the bottom of the hole, wherein the specific gravity of the slurry at the bottom of the hole is 1.15-1.20 after the hole is cleaned, the sand content is less than 2%, and the thickness of the sediment at the bottom of the hole is less than 50 cm.

And (3) measuring the hole by adopting an ultrasonic pore-forming detector, wherein the depth and the aperture of the hole are not less than the design values, and the inclination of the drilled hole is less than 1% of the pile length and not more than 500 mm.

S05: forming a squeezing and expanding branch disc;

and lifting a drill bit of the drilling machine, lowering the giant arm type extruding and expanding support disc machine into the hole, re-measuring the hole depth, extruding and expanding the support disc part of the designed pile, and making an original record. After the squeezing and expanding operation is finished, the equipment is lifted slowly to prevent hole collapse. After each branch disc is squeezed and expanded, slurry should be supplemented in time, the height of a water head in the hole is kept, and hole collapse is prevented.

S06: hole sweeping;

when the soft stratum is filled in the sea, the influence on the soil body is large when the supporting disc is squeezed and expanded, the phenomenon of back silting occurs, and after the squeezing and expanding are completed, a drilling machine is used for drilling and hole sweeping. And when the hole is swept, the drilling operation requirement of the drilling machine of S02 is strictly met.

S07: cleaning and measuring the hole for the second time;

and after hole cleaning is finished, performing second hole cleaning, and removing sediments such as slurry on the wall of the pile casing, drilling slag at the bottom of the hole, silt and the like, wherein the specific gravity of the slurry at the bottom of the hole after hole cleaning is 1.15-1.20, the sand content is less than 2%, and the thickness of the sediment at the bottom of the hole is less than 15 cm.

The double detection is carried out by adopting an ultrasonic pore-forming detector and a caliper, the diameter of a finished disc and the height of a supporting disc are accurately measured, the diameter of the supporting disc is more than 0.95 times of the designed diameter of the supporting disc in sandy soil, and the diameter of the supporting disc is more than 0.9 times of the designed diameter of the supporting disc in cohesive soil.

S08: placing a steel reinforcement cage and hanging a guide pipe;

the shoulder pole type method is adopted for hoisting the steel reinforcement cage, and the steel reinforcement cage is vertically and slowly lowered into a hole during hoisting, so that the collapse of the hole wall is prevented. The bottom of the conduit is lowered to be 30-50 cm away from the bottom of the hole, and the suspension height of the conduit cannot be adjusted randomly.

S09: cleaning the hole for the third time;

after the steel reinforcement cage and the guide pipe are placed, the guide pipe is adopted to carry out air lift or pump suction reverse circulation method in time to be matched with a mud-sand separator for hole cleaning, the specific gravity of the mud at the bottom of the hole after the hole is cleaned for the third time is 1.10-1.15, the sand content is less than 2%, and the thickness of the sediment at the bottom of the hole is less than 15 cm.

S10: pouring underwater concrete;

in the underwater concrete pouring process, the rising height of the concrete surface is frequently measured, the guide pipe is rapidly detached step by step, and the buried depth of the guide pipe is controlled to be 2-6 m. The removed pipe joints need to be cleaned immediately and stacked orderly.

S11: high-pressure grouting;

after the concrete pouring work of the pile body and the supporting disc is finished, the high-pressure grouting pipe is externally connected with high-pressure grouting equipment, and clear water is firstly injected to clean holes. Then, slurry is injected, and the soft soil layer is split under the action of high pressure, so that a soil body reinforcing disc is formed.

The technical solution of the present invention is not limited to the limitations of the above specific embodiments, and all technical modifications made according to the technical solution of the present invention fall within the protection scope of the present invention.