CN212956546U

CN212956546U - Zero displacement underground structure and fender soil device

Info

Publication number: CN212956546U
Application number: CN202021653016.XU
Authority: CN
Inventors: 张继红
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-08-05
Filing date: 2020-08-03
Publication date: 2021-04-13
Anticipated expiration: 2030-08-03
Also published as: CN111749245A

Abstract

The utility model relates to a civil engineering field especially relates to a zero displacement excavation supporting construction and fender soil device in the excavation supporting engineering field, including retaining soil component (6), interior support (7), sack (2), fluid (3), five parts of fluid pressure controlling means (8), sack (2) wherein are the flexible part that possesses splendid attire fluid function, sack (2) are located retaining soil component (6) and between protected object (4), through the soil body stress loss that fluid pressure control compensation excavation construction produced, control the displacement by protected object (4), the utility model discloses can carry out real time control to the displacement by protected object (4), can subtract the foundation ditch construction influence, the cost is low, and the quality is controllable, and degree of safety, reliability are high.

Description

Zero displacement underground structure and fender soil device

Technical Field

The invention relates to the field of foundation pit supporting engineering in the field of civil engineering.

Background

The development of underground space by excavation of foundation pit is the most applied construction form of underground engineering, the construction of subway stations in subway tunnel engineering is usually realized by excavation of foundation pit, and the construction of other underground engineering such as pipe jacking and the like also relates to foundation pit construction engineering. In the foundation pit construction and enclosure engineering, a large number of buildings (structures) needing protection, such as built buildings, underground pipelines, subway tunnels and the like, are often encountered near the foundation pit. Especially, when a house, a subway line, a high-speed rail line and magnetic suspension are distributed near a foundation pit, the protection requirement is very high, and when a precise equipment instrument is met, the harsh protection requirement of zero displacement is sometimes provided. At present, the main technical means for solving the problems is to greatly enhance the strength and rigidity of the foundation pit enclosure structure, so that the construction cost of the foundation pit enclosure construction is very high. The foundation pit enclosure system provides bearing capacity through deformation, so that deformation and displacement of the protected object are still inevitable in the foundation pit construction process no matter how much cost is added on the foundation pit enclosure. In recent years, in a section where deformation control of a protected object is very strict, a servo system has been used to reduce deformation caused by foundation pit construction. However, the biggest problem of the servo system is that concentrated force can only be applied to a supporting position, loading is difficult to be carried out near or below an excavation surface, and loading cannot be carried out before supporting construction and under working conditions of support removal, support replacement, precipitation and the like. The deformation control capability of the protected object is limited. Moreover, for a large amount of used reinforced concrete building envelopes and supporting systems, great deformation is also generated along with the construction and concrete curing period, which are difficult problems which cannot be solved by the prior art.

Disclosure of Invention

The utility model provides a first purpose provides a zero displacement underground structure, this zero displacement underground structure can effectively control the foundation ditch construction and probably arouse the soil body and by the displacement of protected object, finally reaches the quality control target by protected object zero displacement, and the degree of safety is high, and the construction speed is fast, and the cost is low.

The zero-displacement foundation pit supporting structure comprises five parts, namely a soil retaining member, an inner support, a bag, fluid and a fluid pressure control device, wherein the soil retaining member is a retaining structure vertical member which is arranged on the side wall of a foundation pit and embedded into the bottom surface of the foundation pit, the inner support is a structural component which is arranged in the foundation pit and is composed of reinforced concrete or steel members and used for supporting the soil retaining member, the bag is a flexible component with a fluid containing function, the bag is positioned between the soil retaining member and the soil body on the outer side of the soil retaining member or in the soil body on the outer side of an excavation surface of the foundation pit, the fluid is one or a combination of a plurality of gases, liquids or colloids with flowing performance, the fluid is contained in the bag, the fluid pressure control device is a device with a function of adjusting the fluid pressure contained in the bag, and the fluid pressure control.

The utility model provides a second purpose is to provide used zero displacement keeps off native device in the excavation supporting, and this zero displacement keeps off the displacement that the soil body that the native device of effective control foundation ditch construction arouses reaches by the protection object, can retrieve totally or partial recovery recycles, and the cost is low.

The zero-displacement soil retaining device comprises a steel pipe pile, a bag, fluid and a bag connection part, wherein the steel pipe pile is a soil retaining component in foundation pit support, the bag is a flexible part with a fluid containing function, the bag is located on the outer surface of the steel pipe pile, the bag is a part with a function of providing positive pressure and reducing friction force between the steel pipe pile and a soil body, the fluid is one or a combination of a plurality of gases, liquids or colloids with flowing performance contained in the bag, the bag connection part is a part for firmly connecting the bag and the steel pipe pile, and the bag connection part is located near the bottom of the bag.

In the zero-displacement soil retaining device, the bag is a flexible member having a function of gradually separating from the bottom to the top when the steel pipe pile is pulled out.

In the zero-displacement soil retaining device, a lubricant having a function of reducing friction is provided between the bag and the outer surface of the steel pipe pile.

In the zero-displacement soil retaining device, the bag is formed by overlapping two or more layers.

The utility model discloses a zero displacement underground structure and retaining device to keep the soil body stress in the foundation ditch outside certain limit balanced as the starting point in general, the stress boundary condition of the accessible control soil body reaches and is carried out real time control to the displacement by protection object one side soil body and by protection object, can subtract the influence of foundation ditch construction to being protected the object, make the existing building (structure) thing protection technology of civil engineering under the foundation ditch construction condition reach the best, and construction cost is low, the quality is controllable, the degree of safety, the reliability is high.

Drawings

Fig. 1 is a schematic plan view of a first isolation region layout for a first embodiment of the present invention;

fig. 2 is a schematic plan view of a second isolation region layout for use in the first embodiment of the present invention;

fig. 3 is a plan view of a third isolation region used in the first embodiment of the present invention;

figure 4 is a schematic cross-sectional view of a zero displacement retaining structure for use in a first embodiment of the invention;

FIG. 5 is a schematic cross-sectional view of a zero displacement retaining device for use in a second embodiment of the present invention;

fig. 6 is a schematic cross-sectional view illustrating a zero-displacement soil retaining device according to a second embodiment of the present invention.

Detailed Description

As a first embodiment of the present invention, the following description is provided with reference to fig. 1 to 4 to illustrate the zero-displacement supporting structure of the present invention, including the construction method, the working principle and the structural structure thereof. In the first step of the embodiment, the positions of the excavation surface of the foundation pit (5) and the protected object (4) are determined. For the convenience of expression, an isolation area (1) is divided between the excavation surface of the foundation pit (5) and the protected object (4). In the step, the distribution of different protected objects (4) and the relative position relation between the protected objects and the foundation pit (5) are fully known, and the isolation area (1) is divided according to different displacement control requirements. For example, for a linear protected object (4) such as a subway, a high-speed rail, a magnetic levitation, a raw water pipe, etc., the isolation area (1) may be defined along one side of the foundation pit (5) adjacent to the linear protected object (4) and appropriately extended at both sides of the foundation pit (5) approximately perpendicular to the linear protected object (4), as shown in fig. 1. In this step, if the protected object (4) is a building with a limited length such as a house, an isolation area (1) can be defined on the side of the foundation pit (5) adjacent to the protected object (4) and appropriately extended at both ends, as shown in fig. 2. In this step, if the protected object (4) is a point-shaped building and the occupied area is small, if the protected object (4) is a cultural relic such as a ancient tower, an isolation area (1) can be arranged around the protected object (4) under the condition of permission of land use, as shown in fig. 3. The main purpose of the step is to enable the position and the range of the isolation region (1) to be adaptive to the position of the protected object (4) and the protected requirement, establish a model, perform calculation analysis through a finite element method or by utilizing an elastoplasticity mechanics calculation theory, establish a reasonable isolation region (1), enable subsequent work to be economical, feasible and efficient, and meet the displacement control requirement of the protected object (4). The first step of this embodiment is completed and the process proceeds to the second step. In the step, a bag (2) with the function of containing fluid is arranged in the soil body of the isolation area (1). Because the bag (2) is of an elastic structure and can not contain the fluid (3) before being placed, the bag is small in size before being placed into a soil body and is easy to place. The bag (2) can be placed into the soil body by one or a combination of a static method, a hammering method and a vibration method. For example, the bag (2) may be temporarily fixed to a strip structure which is inserted into the soil mass while the bag (2) is inserted into the soil mass. The strip-shaped structure can be recycled. The bag (2) has the function of containing the fluid (3), and in order to improve the effect, the bag (2) has a better function of bearing certain pressure. In the step, holes can be drilled in the soil body, and the bag (2) is folded and placed into the soil body. In the step, one or more bags (2) with the same or different soil penetration depth can be arranged in the isolation area (1). The depth and the size of each bag (2) can be determined through calculation analysis or empirical judgment according to the excavation depth and the size of the foundation pit (5), the structural form of the enclosure of the foundation pit (5) and the displacement control requirement of the protected object (4). In the step, one or more bags (2) can be arranged at the same plane position and different depths, and the bags (2) are communicated with the ground. The main purpose is to provide more displacement control operation segments. Thereby completing the second step of this embodiment and proceeding to the third step. The main operation of the step is to contain the fluid (3) in the bag (2). The method for realizing the step is that the fluid (3) is directly filled through the communicating port between the bag (2) and the ground. The injected fluid (3) can be one or a combination of gases, liquids or colloids. In practice it may be water, air or slurry, etc. In this step, the bag (2) can be filled with solid or granular solid to reduce the dosage of the fluid (3) and prevent the displacement mutation which can be generated by the loss of the fluid (3) to ensure the safety of the control process. The third step of the embodiment is completed, and the fourth step is entered. The method comprises the following steps of applying stress to the soil body on the outer side of the bag (2) through the fluid (3) in the bag (2) and compensating the stress loss of the soil body on one side of the protected object (4) due to the construction of the foundation pit (5). According to the Pascal law, because the fluid (3) is filled in the bag (2) and the bag (2) is elastic, the fluid pressure stress in the bag (2) is transferred to the soil body outside the bag (2). In the excavation process of the foundation pit (5), stress release of an in-situ soil body can be generated in soil body excavation, the stress loss of the soil body on one side of the protected object (4) is compensated through the fluid (3) of the bag (2), and meanwhile, the reaction force of the compensated stress is transmitted to the enclosure structure of the foundation pit (5). In this step, the bag (2) may be sealed and filled with a liquid or gas, and the soil outside the bag (2) is stressed by pressurizing the gas or liquid inside the bag (2). In the step, the stress applied to the soil body outside the bag (2) can be partially or totally more than or less than the stress loss generated by the construction of the foundation pit (5), and the displacement of the protected object (4) is controlled by the superposition effect of stress compensation. In the step, the magnitude and the distribution of stress applied to the soil body on the outer side of the bag (2) can be adjusted in real time by adjusting the pressure of the fluid (3) in the bag (2) in real time according to different working conditions and time of excavation of the foundation pit (5). The fourth step of the present embodiment is completed, and the fifth step is entered. In the step, the displacement of the protected object (4) is controlled by compensating the stress loss of the soil body on one side of the protected object (4). In the step, the stress state of the soil body of the isolation area (1) between the protected object (4) and the foundation pit (5) is adjusted, so that the stability of the stress boundary condition of the soil body in the isolation area (1) is generally maintained, and the displacement of the protected object (4) is controlled. In the concrete implementation, the zero displacement target of the protected object (4) in the excavation process of the foundation pit (5) can be realized by the calculation means such as a finite element method and the like, the arrangement of the isolation region (1), the distribution, the quantity and the depth of the bags (2) and the real-time regulation and control of the pressure of the fluid (3) in the bags (2). In the implementation process, the precision of a calculation means is improved by combining with an observation result, and the expected displacement control target is finally met. The fluid (3) in this embodiment may be one or a combination of liquids, gases, and colloids, and may have a flowing property, for example, slurry may be used as the fluid (3). In this embodiment, the foundation pit construction is one or a combination of several of foundation pit support structure construction, foundation pit excavation construction, foundation pit support replacement construction, foundation pit dewatering construction, underground structure construction, and foundation pit backfill construction. The following section of this embodiment will mainly describe the zero displacement retaining structure used in this embodiment. The zero-displacement foundation pit supporting structure shown in figure 4 is selected and used and comprises five parts, namely a soil retaining member (6), an inner support (7), a bag (2), a fluid (3) and a fluid pressure control device (8), wherein the soil retaining member (6) is a retaining type structural vertical member which is arranged on the side wall of the foundation pit and embedded into the bottom surface of the foundation pit and can be a vertical steel structure or a reinforced concrete structure such as a bored pile, an underground continuous wall, a pile in an SMW construction method, a steel pipe pile, a prefabricated reinforced concrete pile and the like. The inner support (7) is a structural component which is arranged in the foundation pit and is composed of reinforced concrete or steel components and used for supporting the soil retaining component (6), and when the inner support (7) is long, a vertical upright post is arranged in the foundation pit to ensure the vertical stability of the inner support (7). The bag (2) is a flexible part with a fluid containing function, the bag (2) is positioned between the soil retaining member (6) and soil on the outer side of the soil retaining member or in soil on the outer side of an excavation surface of a foundation pit, the fluid (3) is one or a combination of a plurality of gas, liquid or colloid with fluidity, the fluid (3) is contained in the bag (2), the fluid pressure control device (8) is a device with a function of adjusting the fluid pressure contained in the bag (2), the fluid pressure control device (8) is connected with the bag (2), and the fluid pressure control device (8) can be a combination of a fluid input device such as a water pump and a water pipe or a combination of a water tower and the water pipe. In the zero displacement foundation pit engineering, the load required to be considered in the design of a foundation pit supporting structure is larger than the load value selected by the design of a normal foundation pit, and the self-weight load of a soil body can be selected as the soil pressure acting on the soil retaining member (6). The effect of the fluid pressure in the bag (2) is preferably approximately equivalent to the static soil pressure and is preferably not greater than the passive soil pressure. The displacement control caused by the excavation of the foundation pit is controlled in real time, the soil body is difficult to recover once the displacement is generated, the displacement caused by the excavation of the foundation pit can be effectively controlled by controlling the fluid pressure in the bag (2) in real time in the whole process, and the ideal control target of the zero displacement of the foundation pit engineering can be realized by accurate regulation and strict construction operation.

As a second embodiment of the present invention, mainly referring to fig. 5 and fig. 6, a zero-displacement soil retaining device designed in the foundation pit support of the present invention will be described. The zero-displacement soil retaining device comprises four parts, namely a steel pipe pile (9), a bag (2), fluid (3) and a bag connection part (10), wherein the steel pipe pile (9) is a soil retaining component (6) in foundation pit support, the bag (2) is a flexible part with a fluid containing function, the bag (2) is located on the outer surface of the steel pipe pile (9), the bag (2) is a part with a function of providing positive pressure between the steel pipe pile (9) and a soil body and reducing friction force, the fluid (3) is one or a combination of a plurality of gas, liquid or colloid with flowing performance and contained in the bag (2), the bag connection part (10) is a part for firmly connecting the bag (2) and the steel pipe pile (9), and the bag connection part (10) is located near the bottom of the bag (2). In this embodiment, the bag (2) may be a flexible member having a function of gradually separating from the bottom to the top when the steel pipe pile (9) is pulled out. The bag (2) is firmly connected with the steel pipe pile (9), and the construction of the bag (2) can be completed while the steel pipe pile (9) is placed. The bag (2) can be arranged only on the outer side of the excavation surface (11) of the foundation pit as shown in fig. 5 and 6, namely the position of the outer surface (13) of the steel pipe pile facing the soil, and if necessary, the bag (2) can be arranged on the outer surface (12) of the back soil of the steel pipe pile (9) positioned on the inner side of the excavation surface (11) of the foundation pit below the bottom surface of the foundation pit.

This patent includes, but is not limited to, other construction methods that may be substituted by those skilled in the art.

Claims

1. A zero-displacement foundation pit supporting structure is characterized by comprising five parts, namely a soil retaining member (6), an inner support (7), a bag (2), a fluid (3) and a fluid pressure control device (8), wherein the soil retaining member (6) is a supporting and retaining type structural vertical member which is arranged on the side wall of a foundation pit and embedded in the bottom surface of the foundation pit, the inner support (7) is a structural component which is arranged in the foundation pit and is composed of reinforced concrete or steel members and used for supporting the soil retaining member (6), the bag (2) is a flexible component with a fluid containing function, the bag (2) is positioned between the soil retaining member (6) and the soil body on the outer side of the soil retaining member (6) or positioned in the soil body on the outer side of the excavation surface of the foundation pit, the fluid (3) is one or a combination of a plurality of gases, liquids or colloids with fluidity, the fluid (3) is contained in the bag (2), the fluid pressure control device (8) is a device with a function of containing and adjusting the fluid pressure in, the fluid pressure control device (8) is connected with the bag (2).

2. A zero-displacement foundation pit soil retaining device is characterized by comprising four parts, namely a steel pipe pile (9), a bag (2), fluid (3) and a bag connection part (10), wherein the steel pipe pile (9) is a soil retaining component in foundation pit support, the bag (2) is a flexible part with a fluid containing function, the bag (2) is located on the outer surface of the steel pipe pile (9), the bag (2) is a part with a positive pressure providing function between the steel pipe pile (9) and a soil body, the fluid (3) is one or a combination of a plurality of gas, liquid or colloid with fluidity and contained in the bag (2), the bag connection part (10) is a part for firmly connecting the bag (2) and the steel pipe pile (9), and the bag connection part (10) is located near the bottom of the bag (2).

3. The zero-displacement foundation pit soil retaining device according to claim 2, wherein said bag (2) is a flexible member having a property of gradually separating from the bottom to the top when the steel pipe pile (9) is pulled out.

4. The zero-displacement foundation pit soil retaining device according to claim 2, wherein a lubricant having a function of reducing friction is provided between the bag (2) and the outer surface of the steel pipe pile (9).

5. A zero-displacement foundation pit retaining apparatus as claimed in claim 2, wherein said bag (2) is formed by two or more layers of overlapping bags.