RU79299U1 - UNDERGROUND STRUCTURE DEVICE FOR THE CONSTRUCTION OF DENSE CITY BUILDINGS - Google Patents

Abstract

Use: for the construction of underground structures in a dense area in an urban metropolis. Essence: The device of an underground structure for construction of dense urban buildings includes a foundation pit fence located between the foundation of an existing building and a foundation pit fence, a geotechnical barrier in the form of a series of injectors with a diameter of 50-70 mm, vertically installed with the possibility of feeding under pressure a working solution into the soil until the initial stress-strain state of the soil is restored in the area of the existing building. Additionally, a sheet pile wall is installed between the foundation of the existing building and the geotechnical barrier. The tongue-and-groove wall is made of vertically installed metal pipes, or bored piles with a diameter of 200-400 mm with a pitch equal to 1.5-2.0 of the diameter of the pipe or pile, or profiled I-beams with a pitch of 1.5-2 heights vertically installed with a length not less than the depth of the pit I-beams. The device increases the reliability of the structure and ensures the safety of construction work and operation of the building. 1z.pf; 2il.

Description

The utility model relates to construction, namely, the construction of underground structures in the zone of dense development in urban metropolis.

A known design of an underground structure for erecting buildings in the zone of "point" development, containing a protective sheet pile wall of a metal profile and a curtain of clay mortar between the foundation pit and the foundation of an existing building .. / 1 /

This design has increased rigidity, but can not exclude precipitation of the foundations of existing buildings.

The closest design of the underground structure device for building buildings in the urban area is a device containing a foundation pit fence and located between the foundation of the existing building and the foundation pit fence, a geotechnical barrier in the form of a series of injectors installed with the ability to supply working solution under pressure to the ground until stress-strain is restored soil conditions in the zone of an existing building, structure / 2 /.

The disadvantages of such protective structures is the lack of rigidity of the geotechnical barrier, which can not impede large movements of the soil mass in case of emergency situations in the pit, including underground water-bearing

underground utilities, which leads to a collapse of the walls of the pit and precipitation of the existing building.

The technical task is to increase the reliability of the underground structure and ensure the safety of construction work and its operation by preventing the movement of soil towards the open pit during excavation and erection of the foundation in case of emergency during the construction of deep pits.

The problem is solved in such a way that the device of the underground structure in the zone of dense urban development, including the foundation pit fence and located between the foundation of the existing building and the foundation pit fence, is a geotechnical barrier in the form of a series of injectors with a diameter of 50-70 mm installed vertically with the possibility of supplying working solution under pressure soil to restore the original stress-strain state of the soil in the zone of an existing building, according to a utility model, is equipped with an located the foundation of an existing building and a geotechnical barrier, a sheet pile wall made of vertically installed metal pipes of at least at least the depth of the pit, or bored piles with a diameter of 200-400 mm in increments equal to 1.5-2.0 of the diameter of the pipe or pile, or profile I-beams in increments of 1.5-2 I-beam heights. Moreover, between the sheet pile wall and the basement of the building, a geotechnical barrier is additionally installed from a number of injectors installed with the ability to supply working solution under pressure to the soil until its initial stress-strain state is restored during the construction of the sheet pile wall in the area of the foundation pit enclosure.

The proposed device of the underground structure differs from the known one in that it is provided with a sheet pile wall located between the foundation of the existing building and the geotechnical barrier, made of metal pipes vertically installed at least at least the depth of the pit, or bored piles with a diameter of 200-400 mm in increments of 1.5- 2.0 diameters of a pipe or pile, or profile I-beam elements with a step equal to 1.5-2 heights of an I-beam.

The geotechnical barrier allows maintaining the stress-strain state of the soil, and in the event of an emergency, such as a breakthrough of water-bearing underground utilities or poor-quality concrete “walls in the ground” and its collapse, or the formation of karst cavities in the ground, a sheet pile wall works, which prevents the soil from moving sideways pit, and the pitch parameters of the tongue and groove elements selected from the calculation of providing obstacles to movement together with the soil and injectors of the geotechnical barrier.

In addition, for soft soils between the sheet pile wall and the foundation of an existing building, a geotechnical barrier can be additionally mounted from a series of injectors installed with the ability to supply working solution under pressure to the soil until its initial stress-strain state is restored during the installation of the sheet pile wall in the area of the foundation pit enclosure .

When constructing an underground structure for buildings in a dense urban area, soil decompression occurs, which leads to precipitation of foundations of nearby buildings and structures. With the close proximity of construction sites it is almost difficult to influence the stress-strain state

soil. The proposed design of the fence provides two functions at the same time: protective - from soil dumps in the pit, and preventing precipitation of the existing building, which will significantly increase the reliability of the underground structure and ensure the safety of construction work and operation of the building.

Figure 1 shows the device of an underground structure for the construction of buildings of dense urban development; figure 2 - the elements of the sheet pile wall (section); figure 3 is the same as in figure 1 (option with additional geotechnical barrier).

The device of the underground structure consists of a foundation pit fence - a “wall in the ground” 1, the foundation of an existing building 2, a geotechnical barrier 3 from a series of injectors 4 and a sheet pile wall 5 of elements: metal pipes 6, or bored piles 7, or profile I-elements 8. Between sheet pile wall 5 and the foundation of building 2, if necessary (soft soils), additionally arrange a geotechnical barrier 9 from a number of injectors 10.

Example.

Before starting work on the construction of an underground structure, between the enclosing structure of the pit 1 and the foundation 2 of the existing building, a geotechnical barrier 3 is carried out by installing a series of injectors 4 to a depth exceeding the depth of the pit with the possibility of applying a working solution to the soil under pressure and pumping the solution into the ground (filling cementation) . Then, between the foundation of the existing building and the row of injectors 4 of the geotechnical barrier 3, a sheet pile wall 5 is erected by vertically installing metal pipes with a diameter of 320 mm in increments

600 mm, or by arranging a series of bored piles with a diameter of 320 mm with a pitch of 600 mm, or by driving a profile I-beam element, 350 mm high with a pitch of 525 mm, depending on the properties of the soils being used and calculating the rigidity of the structure.

In the presence of weak soils, geotechnical barriers 3 and 9 are arranged on both sides of the sheet pile wall 5. After the sheet pile wall 5 is installed, the first compensating injection cycle is performed to compensate for stresses in the soil mass caused by the sheet pile wall. In soft soils, the first cycle of compensatory injection is carried out through both geotechnical barriers 3 and 9.

This compensates for changes in the stress-strain state arising during excavation of the soil from the excavation, and in emergency situations with the movement of the soil mass. In the process of excavating the soil from the pit, according to the monitoring results, one or two cycles of compensatory pumping are performed. In total, compensation injection is carried out in 3 cycles.

To monitor the change in the stress-strain state of the soil of the base, wells for an inclinometer and a device for measuring layer-by-layer soil deformations are arranged previously, prior to the “wall in the ground” device. In the process of doing the work, we observed the movement of the building envelope and the surrounding soil mass.

Information sources:

1. RF patent No. 2042013, cl. E02D 29/045 publ. 1995.08.20.

2. RF patent №2245966, cl. E02D 31/08, publ. 02/10/2005 (prototype)

Claims (2)

1. An underground structure for erecting buildings in a dense urban area, including a foundation pit fence and located between the foundation of an existing building and a foundation pit fence, a geotechnical barrier in the form of a series of injectors with a diameter of 50-70 mm, vertically installed with the possibility of supplying working solution into the ground under pressure restoration of the initial stress-strain state of the soil in the zone of an existing building, characterized in that the device is equipped with a su the existing building and the geotechnical barrier with a tongue-and-groove wall made of metal pipes or bored piles with a diameter of 200-400 mm vertically installed with a length not less than the depth of the pit with a pitch equal to 1.5-2.0 of the diameter of the pipe or pile, or profile I-elements with a step, equal to 1.5-2.0 heights of the I-beam. 2. The device according to claim 1, characterized in that between the sheet pile wall and the foundation of the building, a geotechnical barrier is additionally mounted from a series of injectors installed with the ability to supply working solution under pressure to the soil until its initial stress-strain state is restored during the installation of the sheet pile wall in pit fencing area.