CN117071587A

CN117071587A - Construction method of foundation pit supporting pile

Info

Publication number: CN117071587A
Application number: CN202311098406.3A
Authority: CN
Inventors: 李华伟
Original assignee: Individual
Current assignee: Individual
Priority date: 2023-08-29
Filing date: 2023-08-29
Publication date: 2023-11-17

Abstract

The invention provides a construction method of foundation pit support piles, which comprises the following steps: defining a foundation pit boundary in the ground red line, and constructing in the foundation pit boundary range; firstly clearing a table, measuring pile positions along the side line of a foundation pit, and constructing supporting piles; if the foundation soil is the mixed filling soil and the plain filling soil, the second row of supporting piles and the third row of supporting piles can be arranged. And excavating a foundation pit after the support pile age is met. According to the construction method, foundation treatment and foundation pit supporting can be completed at one time, the filling materials in the holes are flexible, the supporting piles are filled with active cementing materials, the design requirements of commercial skirt buildings are low, plain soil or building slag can be filled, and the construction cost is reduced.

Description

Construction method of foundation pit supporting pile

Technical Field

The invention belongs to the technical field of foundation pit construction, and particularly relates to a construction method of foundation pit support piles.

Background

In the existing foundation pit construction technology, the schemes such as slope releasing, supporting piles, steel sheet piles, occluding piles, anchor ropes, waist beams, crown beams, soil nails and underground continuous walls are adopted, but for residential communities with intense land, on one hand, the scheme has relatively high engineering cost, each procedure is inserted and operated, the construction period is long, on the other hand, the main building and commercial skirt house have different positions, elevations and design requirements, and are required to be treated independently, so that the construction method is limited by sites and has higher treatment difficulty. Although the rigidity of the foundation pit supporting system can be effectively improved, the deformation of soil around the foundation pit is reduced, and the manufacturing cost of the enclosure structure is increased by the mode.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a construction method of a foundation pit support pile, active cementing materials are filled in through drilling, high-energy layered tamping is used, physical properties of soil are improved through compaction of surrounding soil, active cementing components of large-diameter piles are fully utilized, self-shearing capacity of the piles is improved, and the support effect on the foundation pit is achieved.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

due to the adoption of the technical scheme, the invention has the following advantages and effects:

(1) According to the construction method of the foundation pit supporting pile, foundation treatment and foundation pit supporting can be completed at one time, the filling of the holes is flexible according to different treatment purposes, the supporting pile is filled with active cementing materials, the design requirement of commercial skirt buildings is low, plain soil or building slag can be filled, and the construction cost is reduced.

(2) The construction method of the invention firstly constructs the skirt house and the support piles, fills the support piles with active cementing materials, can directly excavate after completion, does not need to be used as anchor rods, concrete support piles, waist beams and crown beams, and reduces the construction cost.

(3) The construction method of the invention does not need to put slopes in earthwork and do not need to backfill and roll fertilizer grooves for smaller sites with the range of land red lines and foundation pit side lines, and is simple and efficient in construction.

Drawings

Fig. 1 is a flow chart of a construction method of a foundation pit support pile according to the present invention.

Fig. 2 to 5 are construction flow structure diagrams of the present invention.

Fig. 5 is a schematic view of a sectional view of A-A of fig. 4 in a partially enlarged configuration.

Fig. 6 is a perspective view of fig. 4.

Fig. 7 is a construction diagram of an embodiment of the present invention.

In the figure, 1-ground red line; 2-foundation pit side lines; 3-foundation pit; 4-pile body; 5-compacting soil among piles; 6, digging a bottom edge line and 7-supporting piles.

Detailed Description

The following detailed description of the embodiments of the present invention will be provided with reference to the accompanying drawings in order to more clearly understand the objects, features and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the invention, but rather are merely illustrative of the true spirit of the invention.

As shown in fig. 1-6. The invention provides a construction method of foundation pit support piles, which specifically comprises the following steps:

step S1: defining a foundation pit edge line 2 in the land red line 1;

step S2: carrying out supporting pile construction outside the range of the foundation pit side line 2;

specifically, during pile construction, firstly clearing a surface and measuring and placing pile positions to finish the construction of a first row of supporting piles 7, wherein the first row of supporting piles 7 play a supporting role in a foundation pit, so that the stability of a foundation pit slope is ensured, and the foundation pit supporting is replaced;

after the construction of the first row of retaining piles 7 is completed, the construction of the second row or the third row of retaining piles can be carried out in the foundation pit 3, for example, foundation soil is filled with miscellaneous soil and plain soil;

step S3: and excavating the foundation pit 3 to the designed elevation.

Further, the pile construction of the step S2 specifically comprises the following steps of;

step S21: drilling to the construction design depth;

step S22: the rammer is used for impacting and compacting the hole bottom, so that the compaction of the pile end is ensured;

step S23: active cementing materials are filled in the holes in layers, and the holes are tamped and compacted in layers to form supporting piles 7;

as shown in fig. 3. The bottom line 6 is excavated, active cementing materials are filled in the holes to be compacted and compacted to form a high-strength pile body 7 and compacted soil 5 between piles, and the pile is supported, so that the purposes of improving the shear strength of the pile body 4 and improving the physical properties of soil between piles are achieved; the active cementing material is one or a mixture of a plurality of curing agents, lime, cement, solidified soil or bentonite;

step S24: excavating a foundation pit 3 after the age of the support piles 7 is satisfied, wherein the support piles 7 play a role;

further, as one preferable, a plurality of rows of supporting piles 7 may be added for the landfill foundation.

Further, when the pile in the step S2 is constructed, the construction is firstly performed in the area with higher elevation, then the construction is sequentially performed from high elevation to low elevation, and the construction is firstly excavated to the elevation of the bottom of the skirt house.

Examples

As shown in fig. 7. In a certain district of the bridge of the western city, 4 high-rise floors (23F+1, 26F+1 floors), 5 commercial houses (1F) and underground garages (1 floor) are built. The foundation burial depth is-6.5 m, -1.8m and-6.5 m. The field mainly uses the miscellaneous fill, has uneven soil quality and loose structure, and contains a large amount of construction waste and household waste. The part is a waste pile head and a large volume of concrete blocks. The lower part is loess: the yellow brown macroporous structure and wormhole development contain snail shell, mica sheet and sporadic calcareous tuberculosis, and the soil is more uniform. And (5) a hard plastic state. Mainly distributed on the east side and the northwest side of the field. The foundation collapse level is preferably rated class III (severe). The distance between the land red line and the minimum position of the foundation pit boundary is 3-6m. The original design foundation pit supporting scheme is a scheme of reinforced concrete cast-in-place piles, anchor cables, waist beams, crown beams, soil nailing walls, natural slope laying at the east side, net hanging, guniting and the like. Because the field is a mixed filled foundation, the field contains a large number of concrete beams, plates, columns, pile heads and the like, and the construction difficulty of the cast-in-place piles and anchor cables is high. The design scheme is adjusted to be the cement soil supporting pile through expert demonstration.

Design parameters of the cement soil support pile: the ratio is 1:6, the pore-forming diameter is 1.2m, the single-click ramming energy is 600kN.m, the diameter of a rammed compaction pile is 1.8m, the pile length is 12.5m, and the pile completely penetrates through a mixed filled soil layer to enter an old soil layer. Because the project is a mixed filled foundation, a second drainage soil supporting pile is arranged.

Due to site limitation, after construction is completed, straight wall excavation is adopted, and the depth is about 4m. The supporting piles play a good supporting role in the construction period of the foundation of the main building and the underground garage.

Claims

1. The construction method of the foundation pit support pile is characterized by comprising the following steps of: comprising the following steps:

step S1: a foundation pit boundary line (2) is defined in the ground red line (1);

step S2: carrying out supporting pile construction in the range of a foundation pit side line (2);

the method comprises the following steps: firstly, cleaning a table, measuring pile positions, and constructing supporting piles to finish a first row of supporting piles (7);

in the foundation pit (3), foundation soil is filled with mixed soil and plain soil, and the construction of a second row or a third row of support piles can be carried out;

step S3: and excavating the foundation pit (3) to the designed elevation.

2. The method for constructing a foundation pit support pile according to claim 1, wherein:

the pile construction in the step S2 specifically comprises the following steps of;

step S21: drilling to a designed depth;

step S22: impact compaction is carried out on the hole bottom by using a rammer;

step S23: filling compaction soil (5) among piles in layers in the holes, and tamping and compacting in layers to form supporting piles;

step S24: and excavating a foundation pit after the support pile age is satisfied.

3. The method for constructing a foundation pit support pile according to claim 2, wherein:

the inter-pile compaction soil (5) is an active cementing material formed by mixing one or more of curing agents, lime, cement, curing soil or bentonite.

4. A method of constructing a foundation pit support pile according to claim 1 or 2, wherein:

when the pile is constructed, the pile is firstly constructed in a region with higher elevation, and then the pile is sequentially constructed from high elevation to low elevation.