CN111997038A

CN111997038A - Construction method for implementing deep soft soil reinforcement and replacement treatment under throwing and filling block stone layer

Info

Publication number: CN111997038A
Application number: CN202010854192.8A
Authority: CN
Inventors: 丁思华; 丁锦良; 王强
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-08-24
Filing date: 2020-08-24
Publication date: 2020-11-27

Abstract

The invention belongs to the technical field of geotechnical engineering soft soil foundation treatment, and particularly relates to a construction method for implementing soft soil reinforcement and replacement treatment under a throwing and filling thick rock layer in a coastal region, wherein when the throwing and filling rock layer is thick, the particle size of the rock is large, and a soft soil layer under the throwing and filling layer is deep, the construction method comprises the steps of firstly locally excavating the throwing and filling layer, pressing a steel pipe into the soft soil, implanting a slender water filtering pipe with filter cloth at the bottom in a plugging manner, lifting the steel pipe, effectively enriching the pressure difference generated by underground pore water in the radial direction in the water filtering pipe, implanting a water suction device into the bottom of the water filtering pipe, connecting the water suction device with a steel wire hose out of the ground, quickly and intensively discharging underground water into a water collection device by vacuum pumping equipment, completing phase change of an underground soil body, lifting the water filtering pipe and the steel wire hose, tamping discrete bodies into pile holes generated vertically by using discrete materials, or pouring concrete into rigid piles, the foundation with better bearing capacity is formed, and the construction method is also applicable no matter whether the ground has a throwing and filling block stone layer or not.

Description

Construction method for implementing deep soft soil reinforcement and replacement treatment under throwing and filling block stone layer

Technical Field

The invention relates to the field of soft soil foundation treatment of geotechnical engineering, in particular to a construction method for implementing soft soil reinforcement and replacement treatment under a thick rock-filled layer in a coastal region.

Background

Thicker and larger stones are dumped and filled on the soft soil layer surface of the coastal region, so that great difficulty is increased for foundation treatment construction. In the prior art, particularly for throwing and filling block stones on a soft soil layer, in the prior art, a throwing and filling surface layer is firstly treated by using a dynamic compaction, a throwing and filling layer is punctured by using a down-the-hole hammer or a heavy hammer with a pointed end, then pile foundation engineering is implemented, and the construction cost is high. If the soft soil below the cast-fill layer is not treated, the potential danger of post-construction settlement still exists. Therefore, when deep soft soil reinforcement and replacement treatment needs to be carried out under a large-area filling and throwing layer, underground pore water in the soft soil under the filling and throwing layer needs to be drained out of the ground, and the prior art cannot solve the problem.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention aims to provide a construction method for reinforcing and replacing a foundation with deep soft soil having a significant drainage consolidation effect, a short construction period, and a high replacement rate, and being used for reinforcing and replacing soft soil under a large-area cast-and-fill layer, or without a cast-and-fill layer.

In order to achieve the purpose of the invention, the technical scheme of the invention is as follows: a method for reinforcing and replacing deep soft soil under a throwing-filling block stone layer guides underground pore water and air to be enriched in a water filtering pipe and then is pumped out of the ground by vacuum pumping equipment, so that the aim of quickly draining and solidifying a soft soil foundation is fulfilled. It is mainly characterized in that

1) Locally excavating the thrown and filled rock block layer by using an excavator;

2) pressing a steel pipe with a smaller diameter and a movable steel pile tip or a concrete pile tip arranged at the bottom into a soft soil layer;

3) implanting a slender water filtering pipe wrapped with a filter cloth and blocked at the bottom, and filling a water filtering material outside the filter cloth;

4) implanting a water absorption device at the bottom of the slender water filter pipe;

5) connecting the steel wire hose to a pipe network system after going out of the ground;

6) the underground gap water is quickly and intensively discharged to a water collecting device by vacuum pumping equipment;

7) lifting the water filter pipe and the steel wire hose out of the ground;

8) pile holes are used for manufacturing discrete piles or rigid piles.

In the main characteristic 1), the local excavation and throwing-filling block stone layer by the excavator is better to create favorable conditions for sinking the steel pipe, so that a hard block stone throwing-filling layer can be avoided, and a soft soil layer at the lower part is effectively reinforced, therefore, the method is also suitable for a basic construction method for deep and thick soft soil without throwing-filling block stone layer;

in the above main feature 2), it is preferable that the steel pipe with a smaller diameter and a movable steel pile tip or a concrete pile tip is arranged at the bottom of the selected steel pipe, and the smaller the diameter of the steel pipe is, the smaller the volume of the stone layer excavated by the excavator is affected, and the smaller the resistance of the steel pipe to being pressed into soft soil is; if the water filter pipe with smaller diameter is selected, the construction cost can be effectively reduced;

in the above main feature 2), it is preferable that the steel pipe with a smaller diameter and a movable steel pile tip or a concrete pile tip is arranged at the bottom of the steel pipe, and if the movable pile tip is arranged at the bottom of the steel pipe, the soft soil can be prevented from being squeezed into the steel pipe;

in the main characteristic 3), the implanted slender strainer wrapped with the filter cloth and blocked at the bottom is preferably filled with the filter cloth, and the strainer wrapped with the filter cloth and the strainer are filled with the filter material, so that the anti-clogging capability can be improved, and the drainage function of underground pore water can be improved;

in the above main feature 4), the water absorption device is preferably implanted at the bottom of the slender water filter pipe to improve the water absorption efficiency, and the deeper the implantation depth, the better the water absorption effect;

in the above main feature 5), the connecting steel wire hose preferably enters a pipe network system after exiting from the ground, so as to accelerate the centralized drainage effect and shorten the drainage consolidation period;

in the main characteristic 6), the underground gap water is preferably quickly and intensively discharged to the water collecting device by the vacuum pumping equipment, so that the effect of the vacuum pumping equipment can be fully exerted, the construction period is effectively shortened, and the longer the water pumping time is, the better the phase change effect of the soil body is;

in the above main feature 7), preferably, the strainer and the steel wire hose are used as tools when the lifting strainer and the steel wire hose are out of the ground, so as to improve the turnover rate of the tools;

in the above main feature 8), it is preferable to construct discrete piles or rigid piles in the pile holes, and further radially squeeze and expand the soil mass between the piles, and the smaller the pile hole pitch, the shorter the underground pore water stroke, the shorter the drainage consolidation period, the better the effect, the higher the volume replacement rate, and the more the foundation bearing capacity is improved.

The technical scheme of the invention has the beneficial effects that: the technical advantages of avoiding hard rock block filling layers and reinforcing a soft soil layer at the lower part are adopted, effective organized drainage consolidation measures are implemented, underground pore water and air are guided to be enriched in a water filtering pipe firstly, then water is pumped intensively through vacuum pumping equipment, underground water is discharged to a ground water storage device, and the purpose of achieving the effect of fast drainage consolidation of a soft soil foundation is achieved. Therefore, by implementing the technical scheme, the invention can better reinforce the weak soil body at the lower part of the throwing and filling layer, greatly improve the bearing capacity of the foundation, reduce the investment cost and shorten the construction period.

The invention is described in further detail below with reference to the figures and examples.

Drawings

FIG. 1 is a schematic cross-sectional view of the present invention of a hole being formed in a steel pipe in place from an excavated riprap rock layer;

FIG. 2 is a schematic cross-sectional view of the present invention implanted into a strainer after the penetration of the strainer into the ground;

FIG. 3 is a schematic cross-sectional view of the present invention after lifting the steel pipe and drawing water from the filtered water pipe with a vacuum;

FIG. 4 is a schematic cross-sectional view of the water pumping device of the present invention;

FIG. 5 is a schematic plan view of the present invention with a water filtering material filled between the steel pipe and the strainer;

fig. 6 is a schematic plan view of the strainer and the flexible steel hose or the water pumping device according to the present invention.

Detailed Description

The invention relates to a construction method for implementing deep soft soil reinforcement and replacement treatment under a throwing and filling rock layer, which adopts the technical measures of avoiding a hard rock throwing and filling layer and reinforcing a soft soil layer at the lower part to guide underground pore water to be discharged out of the ground, and achieves the purpose of quick water drainage and consolidation effect of a soft soil foundation under special geological conditions. The invention is also suitable for deep soft land without throwing and filling a block stone layer, and has the characteristics of effectively improved bearing capacity, high efficiency, simplicity and environmental protection.

In the construction method implemented by the invention, a riprap rock layer 15 is firstly excavated from the ground 14 to a silt 11 layer, a steel pipe 1 with a movable steel pile tip 5 at the bottom is pressed into a designed elevation, a filter cloth 3 is implanted into a water filter pipe 2 with slender drain holes 4 distributed along the vertical direction of the pipe wall, a water filter material 6 is put between the steel pipe 1 and the water filter pipe 2, underground pore water 12 is radially discharged into the water filter pipe 2 for enrichment, a steel wire hose 7 is implanted to connect a bottom cut and a PVC pipe 13 with holes on the periphery of the pipe to the bottom of a PVC pipe plug 10, the PVC pipe plug 10 is internally threaded with a soft permeable pipe 9, the soft permeable pipe 9 is internally threaded with an upper PVC pipe joint 8, and the PVC pipe joint 8 is connected with the steel wire hose 7.

The preferred embodiments of the present invention disclosed herein and the accompanying drawings, which are readily understood by those skilled in the art as being within the scope of the claims and description of the invention, are not intended to be limiting, and all such modifications, equivalents, improvements and the like are intended to be included within the spirit and scope of the invention.

Claims

1. A construction method for implementing deep soft soil reinforcement and replacement treatment under a throwing and filling block stone layer is mainly characterized in that:

7) lifting the water filter pipe and the steel wire hose out of the ground;

8) pile holes are used for manufacturing discrete piles or rigid piles.

2. The main feature 1) of claim 1, wherein the partial excavation and filling of the rock layer by the excavator is characterized by creating an advantage for sinking the steel pipe to avoid the hard rock filling layer and effectively reinforce the lower soft soil layer, so that the basic construction method is also applicable to the deep soft soil without filling the rock layer.

3. The main characteristic 2) of claim 1, wherein the steel pipe with a smaller diameter and a movable steel pile tip or a concrete pile tip arranged at the bottom is selected, and the smaller the diameter of the steel pipe is, the less the volume of the excavated block stone layer is affected, and the smaller the resistance of the steel pipe to being pressed into soft soil is; if the water filter pipe with smaller diameter is selected, the construction cost is effectively reduced.

4. The main characteristic 2) of claim 1, wherein said steel tube with a smaller diameter and a movable steel or concrete pile tip at the bottom is selected, and the movable pile tip is arranged at the bottom of the steel tube, so that the soft soil can be prevented from being squeezed into the steel tube.

5. The main characteristic 3) of claim 1, wherein the elongated strainer is implanted and wrapped with a filter cloth, and the filter cloth is filled with a filter material, and the strainer is wrapped with a filter cloth and filled with a filter material, so that the anti-clogging capability and the drainage function of underground pore water can be improved.

6. The main characteristic 4) of claim 1, wherein the water absorption device is implanted at the bottom of the slender water filter pipe, and the water absorption efficiency is improved, and the deeper the implantation depth is, the better the water absorption effect is; the longer the pumping time is, the better the phase change effect of the underground soil body is.

7. The main characteristic 5) of claim 1, wherein the steel wire hose is connected to a pipe network system from the ground, and the method is characterized in that the centralized drainage effect is accelerated, and the drainage consolidation period is shortened.

8. The main characteristic 6) of claim 1, wherein the evacuation device is used to quickly and intensively discharge underground water in the gap to the water collecting device, and the efficiency of the evacuation device is fully exerted, so that the construction period is effectively shortened, and the longer the water pumping time is, the better the phase change effect of the soil body is.

9. The main feature 7) of claim 1, wherein the strainer and the flexible steel wire are lifted out of the ground, and the strainer and the flexible steel wire are used as tools to increase the turnover rate of the tools.

10. The main characteristic 8) of claim 1, wherein the pile holes are made into discrete piles or rigid piles, and the soil mass between piles is further radially squeezed and expanded, the smaller the pile hole spacing is, the shorter the underground pore water stroke is, the shorter the drainage consolidation period is, the better the effect is, the higher the volume replacement rate is, and the more the foundation bearing capacity is improved.