阅读说明：本技术 一种在土层夹石块地质条件下基坑支护的方法 (Method for supporting foundation pit under condition of stone block included in soil layer ) 是由 张丽 杨丽颖 潘中奇 于 2020-11-20 设计创作，主要内容包括：一种在土层夹石块地质条件下基坑支护的方法,包括如下步骤：S1,地质勘探,确定基坑开挖路径上石块的位置；S2,对基坑边界测量和定位；S3,钻孔机沿着基坑支护的边界对石块钻取多个钻孔；S4,在钻孔设置支护结构后,开挖表层土方、安装钢围檁和打入钢板桩。本发明用于解决现有对土层中夹石块地质条件基坑支护无法打穿石块,只能对石块进行爆破或破碎,超挖换填后打支护桩,再反开槽施工,造成工程投资急剧增加、工期延长和对周边的道路或房屋造成影响的问题。(A method for supporting a foundation pit under the condition of stone-filled soil geological conditions comprises the following steps: s1, geological exploration is carried out, and the position of a stone block on the excavation path of the foundation pit is determined; s2, measuring and positioning the boundary of the foundation pit; s3, drilling the stone block into a plurality of drill holes by the drilling machine along the boundary of the foundation pit support; s4, after a supporting structure is arranged in the drilled hole, surface earthwork is excavated, a steel enclosure is installed, and a steel sheet pile is driven into the drilled hole. The invention is used for solving the problems that the existing foundation pit support under the geological condition of the stone inclusion blocks in the soil layer can not break through the stone, only can blast or crush the stone, can break the support piles after overbreak and replacement and then carries out reverse grooving construction, thus causing the rapid increase of the engineering investment, the prolonging of the construction period and the influence on the surrounding roads or houses.)

1. A method for supporting a foundation pit under the condition of stone-filled soil geological conditions is characterized by comprising the following steps:

s1, geological exploration is carried out, and the position of a stone block (5) on the excavation path of the foundation pit is determined;

s2, measuring and positioning the boundary of the foundation pit;

s3, drilling the stone block (5) by the drilling machine along the boundary of the foundation pit support to obtain a plurality of drilled holes;

s4, after a supporting structure is drilled, surface earthwork is excavated, a steel enclosure (4) is installed, and a steel sheet pile (1) is driven into the surface earthwork.

2. A method of foundation pit support in the soil-filled stone geological condition as claimed in claim 1, wherein drilling is required through the stone (5) while performing the above step S3.

3. The method for foundation pit support under the condition of soil laminated stone blocks is characterized in that the support structure comprises a protective pipe (2), the protective pipe (2) penetrates through a drilled hole, I-shaped steel (3) is arranged in the protective pipe (2), and cement slurry is filled between the I-shaped steel (3) and the protective pipe (2).

4. A method of supporting a foundation pit in a soil-filled stone block geological condition as claimed in claim 1, wherein in the step S3, the drilling machine drills a large hole in the soil above the stone block (5), inserts the protective tube (2) into the large hole, drills a small hole in the stone block (5), inserts the hydraulic splitter (8) into the small hole, and splits the stone block (5) into a crack by the hydraulic splitter (8).

5. A method for supporting a foundation pit under the condition of soil sandwiching stone blocks as claimed in claim 4, wherein the supporting structure comprises a plurality of inserting plates (7) and connecting plates (6), the connecting plates (6) or both sides of the inserting plates (7) are provided with clamping grooves, after the hydraulic splitting machine (8) splits the stone block (5) into a crack, the pile driver firstly inserts each inserting plate (7) into the crack between two adjacent protecting tubes (2), then the hydraulic splitting machine (8) and the protecting tubes (2) are dismantled, and the connecting plates (6) are inserted into the cracks between the inserting plates (7).

Technical Field

The invention relates to a method for supporting a foundation pit under the condition of stone-filled soil geological conditions.

Background

In the excavation construction process of a newly-built foundation pit, different types of foundation pit supporting structures are widely applied and have forms of I-shaped steel pile supporting, Larsen steel sheet pile supporting, cement mixing pile supporting and the like. When the geological condition that a soil layer contains more large stones is met, the I-steel, Larsen piles or pile heads of cement mixing piles cannot penetrate the stones, the supporting structures cannot be directly applied, the stones can only be blasted or crushed, the supporting piles are driven after overbreak and replacement filling, and then reverse grooving construction is carried out, so that the engineering investment is increased rapidly, the construction period is prolonged, safety accidents are easily caused, and the influence is caused on surrounding roads or houses.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for supporting a foundation pit under the geological condition of stone blocks in a soil layer, which is used for solving the problems that the existing foundation pit support under the geological condition of stone blocks in the soil layer cannot penetrate the stone blocks, only the stone blocks can be blasted or crushed, supporting piles are driven after overbreak and replacement and filling, and then reverse grooving construction is carried out, so that the engineering investment is increased sharply, the construction period is prolonged, and the influence is caused on the surrounding roads or houses.

In order to solve the above problems, the technical solution to be solved by the present invention is:

a method for supporting a foundation pit under the condition of stone-filled soil geological conditions comprises the following steps:

s1, geological exploration is carried out, and the position of a stone block on the excavation path of the foundation pit is determined;

s2, measuring and positioning the boundary of the foundation pit;

s3, drilling the stone block into a plurality of drill holes by the drilling machine along the boundary of the foundation pit support;

s4, after a supporting structure is arranged in the drilled hole, surface earthwork is excavated, a steel enclosure is installed, and a steel sheet pile is driven into the drilled hole.

In carrying out the above step S3, drilling is required through the stone block.

The supporting structure comprises a protective pipe, the protective pipe penetrates through the drilled hole, I-shaped steel is arranged in the protective pipe, and cement paste is filled between the I-shaped steel and the protective pipe.

When the step S3 is carried out, the drilling machine firstly drills a large hole in the soil layer above the stone, then inserts the protective pipe into the large hole, then drills a small hole in the stone, then inserts the hydraulic splitter into the small hole, and splits the stone into a crack by using the hydraulic splitter.

The supporting structure comprises a plurality of inserting plates and a connecting plate, clamping grooves corresponding to the inserting plates are formed in two sides of the connecting plate, after a hydraulic splitter splits a stone into a crack, the pile driver firstly inserts each inserting plate into the crack between two adjacent protective tubes, then the hydraulic splitter and the protective tubes are detached, and the connecting plate is inserted into the gap between the inserting plates.

The invention has the beneficial effects that:

1. the construction cost is low, and the construction period is short. By adopting the method for supporting the foundation pit, the construction cost is reduced by at least more than 40 percent compared with the process of overbreak, replacement, filling and reverse grooving, a plurality of working surfaces can be started simultaneously, the construction period is saved, and the environment is not polluted.

2. The floor area is small, the adaptability to the surrounding terrain is strong, and the safety is high. The foundation pit supporting and excavating device is basically not limited by surrounding terrains and buildings, the excavation safety is high after the foundation pit supporting and excavating is finished, and surrounding roads and buildings cannot be influenced.

3. The supporting structure can be pulled out to realize a recycling process, so that the resource utilization rate is improved, and the consumption of disposable materials is reduced as much as possible.

4. The spacing of the supporting structure can be adjusted by structure calculation according to the depth of the foundation pit, and the adaptability is strong.

Drawings

The invention is further described below with reference to the accompanying drawings:

FIG. 1 is a schematic top view of the structure of embodiment 1,

FIG. 2 is a schematic front view showing the structure of embodiment 1,

FIG. 3 is a schematic top view showing the structure of the embodiment 2,

FIG. 4 is a schematic front view partially in section of the structure of example 2,

FIG. 5 is a partial sectional view schematically showing the structure of example 2,

fig. 6 is a partial schematic top view of the structure of embodiment 2.

In the figure: the steel sheet pile comprises a steel sheet pile 1, a protective pipe 2, I-shaped steel 3, a steel enclosure 4, a stone block 5, a connecting plate 6, an inserting plate 7 and a hydraulic splitter 8.

Detailed Description

A method for supporting a foundation pit under the condition of stone-filled soil geological conditions comprises the following steps:

s1, geological exploration is carried out, and the position of the stone block 5 on the excavation path of the foundation pit is determined;

s2, measuring the boundary of the foundation pit and positioning the foundation pit by paying off;

s3, the drill drills a plurality of holes into the stone block 5 along the boundary of the foundation pit support;

and S4, after a supporting structure is drilled, excavating surface earthwork, installing a steel enclosure 4 and driving a steel sheet pile 1.

The following two types of supporting structures are further described:

example 1:

as shown in fig. 3 and 4, when the thickness of the stone block 5 is less than 1m, a supporting structure consisting of a PE protection pipe 2 and an i-steel 3 can be used, in the implementation, as shown in fig. 1 and 2, a drilling machine drills the stone block 5 through, then lubricating oil is smeared on the inner wall of the protection pipe 2, the protection pipe 2 is inserted into a drilled hole, the i-steel 3 is placed in the drilled hole, cement paste is filled between the i-steel 3 and the protection pipe 2, after the cement paste is solidified, earthwork or stone with the surface layer of the soil layer being about 50cm is excavated, a steel enclosure 4 and a driven steel sheet pile 1 are installed, and after excavation of a foundation pit is completed, the PE protection pipe 2 and the i-steel 3 are pulled out for reuse through a pile driver.

Example 2:

when the thickness of the stone block 5 is more than 1m and the drilling machine difficultly drills through the stone block 5, a supporting structure consisting of a plurality of inserting plates 7, connecting plates 6 and steel protecting tubes 2 can be used, in the implementation, as shown in fig. 5 and 6, after a large hole is drilled in an earth layer above the stone block 5 by the drilling machine, the steel protecting tubes 2 are inserted into the large hole, then a small hole is drilled in the stone block 5, then a hydraulic splitter 8 is inserted into the small hole, after the stone block 5 is split into a crack with the width of 2-3 cm by the plurality of hydraulic splitters 8, each inserting plate 7 is inserted into the crack between two adjacent protecting tubes 2 by the pile driver, then the hydraulic splitters 8 and the protecting tubes 2 are removed, the connecting plates 6 are inserted into the gaps between the pile driving inserting plates 7, the two sides of the inserting plates 7 are required to be positioned in the clamping grooves of the connecting plates 6, the inserting plates 7 are clamped and fixed by the stone block 5 and the earth layer, then the, and finishing the installation of the support around the foundation pit.