CN209636826U - Water-stop structure of foundation pit in water-rich sand and gravel stratum - Google Patents

Abstract

The present application relates to a water-stop structure for a foundation pit in a water-rich sandy gravel stratum, which is arranged in the foundation pit of the stratum. And the horizontal water-stop curtain arranged at the bottom of the foundation pit; the vertical water-stop curtain includes a composite pile foundation and a vertical sleeve valve pipe grouting body, the composite pile foundation surrounds the outer periphery of the side wall of the foundation pit, and passes through the vertical Sleeve valve pipe grouting body overlap. The water-stop structure of foundation pits in water-rich sand and gravel strata provided by this application adopts a combination of vertical water-stop curtains and horizontal water-stop curtains, which can effectively solve the problem that the suspended water-stop curtains and pit precipitation schemes cannot meet the requirements of water-rich sand and gravel strata. The excavation of the foundation pit and the safety of surrounding buildings; at the same time, the vertical combined water-stop curtain formed by the composite pile foundation and the vertical sleeve valve pipe grouting body is easy to construct and has a good water-stop effect; in addition, the high-pressure rotary grouting pile and The composite pile foundation formed by the combination of micro-steel pipes can simultaneously play the role of water-stop curtain and foundation pit support, and does not need to be separately constructed as a support structure.

Description

Water-stop structure of foundation pit in water-rich sand and gravel stratum

technical field

The utility model relates to the technical field of building construction, in particular to a water-stop structure for foundation pits in water-rich sand and gravel strata.

Background technique

With the acceleration of my country's urbanization process and the continuous improvement of people's requirements for the environment and scenery of residential areas, lake areas and ancient river tidal flat areas that were abandoned in the past have now become the preferred locations for residential construction projects. Generally, the groundwater in lake areas and ancient rivers is very rich, and there are deep gravel or pebble layers. Carry out waterproofing and drainage and reinforcement treatment.

For foundation pits in water-rich sand and gravel strata, according to the traditional construction method, it is necessary to dewater in the foundation pit during construction. Since the foundation sand and gravel soil layer structure is relatively loose and has strong permeability, if the foundation is not reinforced, the foundation pit will be excavated. Problems such as water gushing or seepage damage are prone to occur. At the same time, excessive reduction of groundwater will also cause large consolidation and settlement of the surrounding soil, which will affect the safe use of buildings.

Utility model content

Based on this, a water-stopping structure for a foundation pit in a water-rich sandy gravel stratum is provided to ensure the safety of foundation pit excavation.

A foundation pit water-stopping structure of water-rich sand and gravel stratum is arranged in the foundation pit of the stratum, and the water-stop structure of foundation pit of water-rich sand and gravel stratum comprises:

a vertical water-stop curtain arranged on the outer periphery of the side wall in the foundation pit; and

A horizontal water-stop curtain arranged at the bottom of the foundation pit;

Wherein, the vertical water-stop curtain includes a composite pile foundation and a vertical sleeve valve pipe grouting body. Slurry lap.

In one of the embodiments, the horizontal water-stop curtain is configured as a combination of horizontal sleeve valve pipe grouting bodies formed by sleeve valve pipe grouting.

In one of the embodiments, the vertical water-stop curtain and the horizontal water-stop curtain are overlapped by the respective vertical sleeve valve pipe grouting body and the horizontal sleeve valve pipe grouting body to form the The closed water stop system of the foundation pit.

In one of the embodiments, the composite pile foundation is constructed as a combination of high-pressure jet spray piles and micro-steel pipes.

In one of the embodiments, the composite pile foundation is constructed as a high-pressure rotary grouting pile using triple tube high-pressure rotary grouting grouting, and micro steel pipes are driven into the high-pressure rotary grouting pile.

In one of the embodiments, the micro-steel pipe is configured as a seamless steel pipe arranged at the center of the high-pressure jet-spray pile along the length direction of the high-pressure jet-spray pile.

In one of the embodiments, the grouting body of the vertical sleeve valve pipe overlaps in the gap between two adjacent high-pressure jet grouting piles.

In one embodiment, the sleeve valve tubes of the vertical sleeve valve tube grouting body and the horizontal sleeve valve tube grouting body are flexible plastic tubes.

In one of the embodiments, the horizontal water-stop curtain is configured to be formed by grouting several static pressure grouting holes arranged in a quincunx shape at the bottom of the foundation pit.

In one of the embodiments, the water-stopping structure of the foundation pit of the water-rich sand and gravel formation is set in the foundation pit of the water-rich sand and gravel formation

The water-stop structure of foundation pits in water-rich sand and gravel strata provided by this application adopts a combination of vertical water-stop curtains and horizontal water-stop curtains, which can effectively solve the problem that the suspended water-stop curtains and pit precipitation schemes cannot meet the requirements of water-rich sand and gravel strata. The excavation of the foundation pit and the safety of surrounding buildings; at the same time, the vertical combined water-stop curtain formed by the composite pile foundation and the vertical sleeve valve pipe grouting body is easy to construct and has a good water-stop effect, which can save construction time and reduce construction costs; In addition, the composite pile foundation formed by the combination of high-pressure rotary grouting piles and micro-steel pipes can simultaneously play the role of water-stop curtain and foundation pit support, and does not need to be separately constructed as a support structure.

Description of drawings

Fig. 1 is the structural sectional view of foundation pit construction in an embodiment of the utility model;

Fig. 2 is a structural plan view of the foundation pit construction shown in Fig. 1 .

Detailed ways

In order to facilitate the understanding of the utility model, the utility model will be described more fully below with reference to the relevant drawings. Preferred embodiments of the utility model are provided in the accompanying drawings. However, the invention can be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present utility model more thorough and comprehensive.

It should be noted that when an element is said to be "fixed" to another element, it may be directly on the other element or there may be an element in between. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be both elements in between.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of this invention. The terminology used in the description of the utility model herein is only for the purpose of describing specific embodiments, and is not intended to limit the utility model. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Also, in the specification, the phrase "schematic plan view" refers to a drawing when a target portion is viewed from above. And the drawings are not drawn in a 1:1 scale, and the relative sizes of the elements are drawn in the drawings for example only, not necessarily drawn in true scale.

The foundation pit is an earth pit excavated at the foundation design position according to the base level and foundation plane size. Before excavation, the excavation plan should be determined according to the geological and hydrological data, combined with the conditions of the nearby buildings, and the waterproof and drainage work should be done well.

In particular, when carrying out foundation pit construction for strata with loose soil structure and strong permeability (such as water-rich sandy gravel stratum), the commonly used hanging water-stop curtain and the precipitation scheme in the pit are difficult to meet the needs of foundation pit excavation and surrounding buildings. The need for material safety, and the cost of the bottom-type water-stop curtain is high, and the construction quality and water-stop effect cannot be guaranteed.

Therefore, it is necessary to provide a water-stop structure for foundation pits in water-rich sand and gravel strata that ensures the safety of foundation pit excavation.

Taking the water-rich sand and gravel stratum as an example, the water-stop structure of the foundation pit in this application will be described in detail below. This embodiment is only used as an example for illustration, and does not limit the technical scope of this application. Furthermore, unnecessary components are omitted in the drawings of the embodiments to clearly show the technical features of the present application. It can be understood that, in some other embodiments, the water-stop structure for foundation pits in water-rich sand and gravel formations in the present application can also be used in the construction of other loose formations, which is not limited here.

Before describing the application in detail, some content in the application is explained first, so as to understand the technical solution of the application more clearly.

The water-stop curtain is a concept, which is the general term for the water-stop series around the main body of the project. It is a continuous water-stop body used to prevent or reduce the groundwater on the side wall of the foundation pit and the groundwater at the bottom of the foundation pit from flowing into the foundation pit.

Hereinafter, the water-stopping structure for foundation pits in water-rich sand and gravel formations in the embodiments of the present application will be described in detail with reference to the accompanying drawings.

Fig. 1 has shown the structural sectional view of foundation pit construction in an embodiment of the present utility model; Fig. 2 has shown the structural plan view of foundation pit construction in an embodiment of the present utility model; For ease of description, accompanying drawing has only shown and The structure related to the embodiment of this application.

Please refer to Fig. 1 and Fig. 2, in an embodiment of the utility model, the water-stopping structure 100 of the foundation pit of the water-rich gravel stratum 200 is arranged in the foundation pit 300 of the water-rich gravel stratum 200, so as to form a fully enclosed surrounding around the periphery of the foundation pit 300 The water stop system, and at the same time constitute the support system of the foundation pit 300.

The foundation pit 300 includes a bottom 301 and sidewalls 303 surrounding the bottom 301 . The foundation pit water-stop structure 100 in water-rich sand and gravel stratum includes a vertical water-stop curtain 10 arranged on the outer periphery of the side wall 303 of the foundation pit 300 and a horizontal water-stop curtain 30 arranged on the bottom 301 of the foundation pit 300 .

Specifically, the vertical water-stop curtain 10 includes a composite pile foundation 11 and a vertical sleeve valve pipe grouting body 13 . The composite pile foundation 11 surrounds the outer periphery of the side wall 303 and is overlapped by the vertical sleeve valve pipe grouting body 13 . The horizontal sleeve valve pipe grouting body 31 is formed by grouting the sleeve valve pipe horizontally to the water-stop curtain 30 . At the same time, the vertical water-stop curtain 10 and the horizontal water-stop curtain 30 are overlapped by respective vertical sleeve valve pipe grouting body 13 and horizontal sleeve valve pipe grouting body 31 to form a closed water-stop system of the foundation pit 300 .

In this specific embodiment, the composite pile foundation 11 in the vertical water-stop curtain 10 is a combination of a high-pressure rotary grouting pile 110 and a micro steel pipe 112 . In the construction process, after the high-pressure rotary grouting pile 110 is constructed by triple-pipe high-pressure rotary grouting grouting, micro steel pipes 112 are driven into the high-pressure rotary grouting pile 110 . Specifically, the micro steel pipe 112 is arranged at the center of the high pressure rotary grouting pile 110 along the length direction of the high pressure rotary grouting pile 110, and the micro steel pipe 112 is a seamless steel pipe with a diameter of 108 mm and a wall thickness of 6 mm. Understandably, in some other embodiments, the composite pile foundation 11 may be a composite structure of other pile structures, which is not limited here.

The horizontal water-stop curtain 30 in this specific embodiment is that several static pressure grouting holes are arranged in a quincunx shape at the bottom of the foundation pit 300 during construction, and when the grouting of the several static pressure grouting holes is completed, they are jointly formed. Specifically, the distance between every two adjacent static pressure grouting holes is 1.5m, and the sleeve valve pipe adopts a flexible plastic pipe with a diameter of 76mm.

During construction, release the specific pile positions of the high-pressure jet grouting piles 110 around the foundation pit 300 in the water-rich sand and gravel formation 200, repeatedly measure the hole positions of the high-pressure jet grouting piles 110, mark the pile positions with markers, measure each The length of the drill pipe is numbered sequentially with red paint, and the depth control red line is marked with red paint on the wall of the uppermost drill pipe.

Move the triple tube high-pressure rotary grouting pile machine to the designated pile position, align the drill bit with the center of the hole position of the high-pressure rotary grouting pile 110, control the verticality deviation of the drill pipe within 1% to 1.5%, and drill the drill bit at the predetermined pile position to The design elevation, the bore hole diameter is 150mm; at the same time, the hole positions of the high-pressure jet grouting piles 110 are evenly arranged along the foundation pit 300, and the hole depth is 3012.0m lower than the bottom of the foundation pit 300. A seamless steel pipe with a diameter of 108mm and a thickness of 6mm is driven into the center of the spray pile 110 to form a micro-steel pipe 112 pile core. The length of each steel pipe is 3m. Composite pile foundation 11.

Then arrange the static pressure grouting holes along the outside of the high-pressure rotary grouting pile 110 in the foundation pit 300, and the distance between two adjacent static pressure grouting holes is 1.0m; after the grouting is completed, the vertical sleeve valve pipe grouting body 13 is located Between the gaps between two adjacent high-pressure rotary grouting piles 110 , and overlapping with two adjacent high-pressure rotary grouting piles 110 at intervals. In this way, the vertical waterproof curtain 10 located on the outer periphery of the side wall 303 in the foundation pit 300 is formed.

At the bottom 301 of the foundation pit 300, several static pressure grouting holes are arranged in a quincunx shape, and the distance between two adjacent static pressure grouting holes is 1.5m. , and when drilling 2m and after that, the drilling rig needs to be leveled and corrected for every additional section of drill pipe, and the inclination of the drill hole is required to be ≤1%. At the same time, the sleeve valve pipe adopts a flexible plastic pipe with a diameter of 76mm. (that is, the bottom 301 of the foundation pit 300) adopts flower tubes with overflow holes, and the non-grouting area (that is, the inside of the foundation pit 300) adopts non-flower tubes without overflow holes. After reaching the design value and stabilizing the pressure for 20 minutes, one of the above conditions for the end of sleeve valve grouting can be used as the end standard of single hole grouting. In this way, a horizontal water-stop curtain at the bottom 301 of the foundation pit 300 is formed; and the vertical water-stop curtain 10 overlaps with the horizontal water-stop curtain 30 to form a joint water-stop system of the foundation pit 300 .

The water-stop structure 100 for foundation pits in water-rich sand and gravel strata provided in this application has the following beneficial effects:

1. The scheme of combining the vertical water-stop curtain 10 and the horizontal water-stop curtain 30 can effectively solve the problem that the suspended water-stop curtain and the precipitation scheme in the pit cannot meet the needs of excavation of foundation pits in water-rich sand and gravel strata and the safety of surrounding buildings , but the bottom-type water-stop curtain is costly, and a series of problems such as construction quality and water-stop effect cannot be guaranteed;

2. The vertical joint water-stop curtain formed by the composite pile foundation 11 and the vertical sleeve valve pipe grouting body 13 is easy to construct and has a good water-stop effect, which can save the construction period and reduce the cost;

3. The composite pile foundation formed by the combination of high-pressure rotary grouting pile 110 and micro-steel pipe 112 can play the role of water-stop curtain and foundation pit 300 support at the same time, and does not need to be used as a separate support structure;

4. For high-pressure grouting (high-pressure rotary jet grouting), it is suitable for sandy soil, cohesive soil, silty soil and other strata, and static pressure grouting (sleeve valve grouting) is suitable for medium-coarse sand, gravel, broken rock and other geology However, the actual stratum is usually dominated by a certain rock-soil layer, and various rock-soil layers and various geological conditions coexist. It is difficult for the existing single grouting method to meet the characteristics of various strata at the same time. Combined dynamic and static grouting The method (high-pressure rotary grouting pile grouting and sleeve valve pipe static pressure grouting) can effectively improve the effect of grouting reinforcement.

The above-mentioned embodiments only express several implementations of the utility model, and the description thereof is relatively specific and detailed, but it should not be construed as limiting the patent scope of the utility model. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the scope of protection of the utility model patent should be based on the appended claims.

Claims (10)

1. A water-stop water-stop structure for a foundation pit in a water-rich sandy gravel formation, which is arranged in the foundation pit of the formation, is characterized in that, the water-stop structure for a foundation pit in a water-rich sandy gravel formation comprises: a vertical water-stop curtain arranged on the outer periphery of the side wall in the foundation pit; and A horizontal water-stop curtain arranged at the bottom of the foundation pit; Wherein, the vertical water-stop curtain includes a composite pile foundation and a vertical sleeve valve pipe grouting body. Slurry lap. 2. The water-stop structure for foundation pits in water-rich sand and gravel formations according to claim 1, wherein the horizontal water-stop curtain is constructed as a combination of horizontal sleeve valve pipe grouting bodies formed by sleeve valve pipe grouting. 3. The water-stop structure for foundation pits in water-rich sand and gravel strata according to claim 2, wherein the vertical water-stop curtain and the horizontal water-stop curtain are injected through the respective vertical sleeve valve pipes. The grout overlaps with the grouting body of the horizontal sleeve valve pipe to form a closed water-stop system for the foundation pit. 4. The water-stop structure for foundation pits in water-rich sand and gravel strata according to claim 1, characterized in that, the composite pile foundation structure is a combination of high-pressure rotary grouting piles and micro-steel pipes. 5. The water-stop structure for foundation pits in water-rich sand and gravel strata according to claim 1, wherein the composite pile foundation is constructed as a high-pressure rotary grouting pile using triple tube high-pressure rotary jet grouting, and the Micro-steel pipes are driven into high-pressure rotary grouting piles. 6. The water-stop structure for foundation pits in water-rich sand and gravel strata according to any one of claims 4 or 5, wherein the micro-steel pipes are configured to be arranged on the high-pressure rotary grouting pile along the length direction of the high-pressure rotary grouting pile. Seamless steel pipe in the center of the spray pile. 7. The water-stop structure for foundation pits in water-rich sand and gravel formations according to any one of claims 4 or 5, wherein the vertical sleeve valve pipe grouting body overlaps two adjacent high-pressure rotary In the gap between spray piles. 8. The water-stopping structure for foundation pits in water-rich sand and gravel strata according to claim 2, characterized in that the sleeves of the vertical sleeve valve pipe grouting body and the horizontal sleeve valve pipe grouting body during grouting The valve tube is a flexible plastic tube. 9. The foundation pit water-stop structure in water-rich sand and gravel stratum according to claim 1, characterized in that, the horizontal water-stop curtain is configured as several static pressure grouting holes arranged in a quincunx shape on the bottom of the foundation pit Grout formed. 10. The water-stop structure for foundation pits in water-rich sand and gravel formations according to claim 1, characterized in that the water-stop structure for foundation pits in water-rich sand and gravel formations is set in the foundation pits in water-rich sand and gravel formations.