CN-117188464-B - Construction method of pile body structure for composite foundation

Abstract

The invention belongs to the technical field of civil engineering, and particularly provides a prefabricated pile cap which comprises a pile cap body, wherein a pile cap protrusion is arranged at the bottom of the pile cap body, a grouting pipeline is arranged in the pile cap body and penetrates through the pile cap body, a slurry circulation groove is formed in the bottom surface of the pile cap body, and the slurry circulation groove is communicated with the grouting pipeline. The invention also provides a pile body structure for the composite foundation and a construction method thereof, wherein the prefabricated pile cap and the pile body form a concave-convex connection mode, the pile cap is small in eccentricity, good in connection reliability with the pile head and capable of being tightly attached to the pile Zhou Yantu. The construction method is simple, high in efficiency, capable of avoiding complex procedures of pile head leveling, and has the advantages of small pile body damage, convenience in hoisting, low economic time cost and the like.

Inventors

• Zhai shun
• XU QIXIANG
• WANG YINGHE
• YU ZHIPENG
• WANG XIANG
• LI SHILIANG
• HUANG GUOLIANG
• XIONG SHIJIE
• HUANG HONGHUA
• LI WEI

Assignees

• 中铁第四勘察设计院集团有限公司

Dates

Publication Date

20260505

Application Date

20230828

Claims (6)

1. 1. A construction method of a pile body structure for a composite foundation is characterized by comprising a pile body and a prefabricated pile cap, wherein the prefabricated pile cap comprises a pile cap body, a pile cap protrusion is arranged at the bottom of the pile cap body, a grouting pipeline is arranged in the pile cap body and penetrates through the pile cap body, a slurry circulation groove is formed in the bottom surface of the pile cap body and communicated with the grouting pipeline, a groove matched with the pile cap protrusion is formed in the top of the pile body, the pile cap body is mounted on the pile body, the pile cap protrusion is inserted into the groove, the grouting pipeline is communicated with the groove, and the construction method comprises the following steps: (1) Pouring a prefabricated pile cap; (2) Leveling and rolling the ground to the designed elevation of the top surface of the pile cap; (3) Drilling and pouring the pile body; (4) The pile head leveling forming box is arranged on the pile top concrete surface, the pile head leveling forming box is pressed downwards until the top surface of the pile head leveling forming box is leveled with the ground after leveling, the pile head leveling forming box is adjusted to be horizontal through observing the level bubble, and the pile head leveling forming box is taken out after the concrete strength of the pile body reaches the standard; (5) Digging out soil around the pile top to form a space for accommodating the prefabricated pile cap, and cleaning slag soil on the surface of the pile top; (6) Hoisting the prefabricated pile cap to the upper part of the pile top, and inserting the pile cap bulge into the pile top groove; (7) Grouting is carried out on the joint of the prefabricated pile cap and the pile body through a grouting pipeline arranged on the pile cap body until grout overflows from the periphery of the prefabricated pile cap, grouting is stopped, and pile body structure construction is completed.
2. 2. The method for constructing a pile structure of a composite foundation according to claim 1, wherein a hoisting ring is provided on the top of the pile cap body.
3. 3. The construction method of pile body structure for composite foundation according to claim 1, wherein the pile cap protrusion is cylindrical, and the diameter of the groove is larger than the diameter of the pile cap protrusion.
4. 4. The construction method of pile body structure for composite foundation according to claim 1, wherein the step (3) is specifically drilling, pouring concrete to above the designed elevation of pile top, removing drill slag, vibrating the concrete, scooping out surface layer slurry, scooping out superfilling concrete until the concrete surface is no longer lowered, and making the concrete surface reach the designed elevation of pile top.
5. 5. The construction method of pile structure for composite foundation according to claim 1, wherein the top of the box body is provided with a pull ring.
6. 6. The construction method of pile body structure for composite foundation according to claim 1, wherein a plurality of grouting pipes are provided on the precast pile cap, and in the step (7), one of the grouting pipes is used as an exhaust hole in grouting, and after the rest of grouting pipes are filled, the grouting pipe used as an exhaust hole is filled with slurry.

Description

Construction method of pile body structure for composite foundation Technical Field The invention belongs to the technical field of civil engineering, and particularly relates to a prefabricated pile cap, a pile body structure for a composite foundation and a construction method of the pile body structure. Background The CFG pile foundation treatment is used as a common composite foundation treatment technology, so that the bearing performance of the pile body can be fully exerted, and the natural bearing capacity of soil between piles can be utilized to a greater extent. The CFG pile body structure mainly comprises pile body, pile cap, mattress cushion and other structures. The pile cap is used as a key structure for effectively preventing the pile body from being excessively penetrated, has various structural forms and construction methods, and is mainly divided into cast-in-situ pile caps and prefabricated pile cap technologies. The cast-in-situ pile cap construction technology is developed more mature, however, the cast-in-situ pile cap assembly construction degree is low, the maintenance time is long, and the construction requirement is difficult to meet when the construction period is short. The prefabricated pile cap has good maintenance conditions, the quality of the pile cap is guaranteed, the maintenance time of the on-site pile cap can be greatly reduced, and the construction period is greatly shortened, but the existing prefabricated pile cap still has the problems that 1, the connection reliability of the prefabricated pile cap and the pile head of the CFG pile is poor, no effective connection mode exists, or the prefabricated pile cap is installed through a complex buckle structure, the construction precision requirement is high, the prefabricated pile cap is mainly suitable for prefabricated piles, the applicability to cast-in-situ piles is poor, 2, the pile head is uneven, the problems of pile cap shaking, offset, uneven stress and the like are easily caused, the construction quality is influenced, 3, when the pile cap is rotationally excavated to form a soil mold, the excessive rotational excavation phenomenon is common due to the poor construction precision, gaps exist between the pile cap and soil around the pile cap, the pile cap is not manually tamped, the adverse effect is caused on the pile cap stress, and the pile cap is inclined when the pile cap is serious. Therefore, it is necessary to research a prefabricated pile cap structure and a construction method, wherein the pile head and the pile cap are connected simply and reliably, the pile top is easy to level, and the pile cap and the pile surrounding soil are tightly attached. Disclosure of Invention The invention aims to solve the problems of poor connection reliability of the pile head and the pile cap, difficult close compaction with surrounding soil of the pile, complicated leveling procedure of the pile head and the like in the prior art. The invention provides a prefabricated pile cap which comprises a pile cap body, wherein a pile cap protrusion is arranged at the bottom of the pile cap body, a grouting pipeline is arranged in the pile cap body and penetrates through the pile cap body, a slurry circulation groove is formed in the bottom surface of the pile cap body, and the slurry circulation groove is communicated with the grouting pipeline. Specifically, the top of the pile cap body is provided with a hoisting ring. The invention also provides a pile body structure for the composite foundation, which comprises a pile body and the prefabricated pile cap, wherein a groove matched with the pile cap bulge is formed in the top of the pile body, the pile cap body is arranged on the pile body, the pile cap bulge is inserted into the groove, and the grouting pipeline is communicated with the groove. Specifically, the pile cap protrusion is cylindrical, and the diameter of the groove is larger than that of the pile cap protrusion. The invention also provides a construction method of the pile body structure for the composite foundation, which comprises the following steps: (1) Pouring a prefabricated pile cap; (2) Leveling and rolling the ground to the designed elevation of the top surface of the pile cap; (3) Drilling and pouring the pile body; (4) Leveling the pile head and forming a groove; (5) Digging out soil around the pile top to form a space for accommodating the prefabricated pile cap, and cleaning slag soil on the surface of the pile top; (6) Hoisting the prefabricated pile cap to the upper part of the pile top, and inserting the pile cap bulge into the pile top groove; (7) Grouting is carried out on the joint of the pile cap and the pile body through a grouting pipeline arranged on the pile cap body until grout overflows from the periphery of the pile cap, grouting is stopped, and pile body structure construction is completed. Specifically, the step (3) comprises the steps of drilling holes, pouring concrete to a position