CN205444215U - Gas drive foundation pit dewatering system - Google Patents

Abstract

The utility model provides a gas drive foundation pit dewatering system, relates to civil engineering technical field, and that solve is the technical problem who improves low permeability soil layer dry out efficiency. This system includes vacuum tubular well unit, gas injection well unit, vacuum tubular well unit includes to be backfilled the filter material between the outer pipe wall of the soil body of foundation ditch and precipitation well casing, chimney filter, sediment tube and forms the filter material layer from last precipitation well casing, chimney filter, the sediment tube that concatenates in proper order extremely down to the backfill face closing cap on this filter material layer has clay sealing layer, is equipped with immersible pump, level gauge in the chimney filter, the gas injection well unit includes injection syringe, outlet duct, high pressurized air source is received to the upper end mouth of pipe of injection syringe, the upper end mouth of pipe of outlet duct and the butt joint of the lower extreme mouth of pipe of injection syringe, and the pipe wall of outlet duct is ventilative. The system provided by the utility model, the precipitation of specially adapted low permeability soil layer.

Description

Gas drive base pit dewatering system

Technical field

This utility model relates to civil engineering technology, particularly relates to the technology of a kind of gas drive base pit dewatering system.

Background technology

Being dried and safe construction environment for providing to deep-foundation pit engineering, using the method reduction excavation soil layer of precipitation is the most necessary with the level of ground water in the water-bearing layer that base plate of foundation pit pressure-bearing Shuitu may be caused to gush.Deep because of cutting depth at soft clay area deep-foundation pit engineering, the general water level used in pipe well reduction water-bearing layer or water content.

But soft clay area soil nature changes greatly, when being positioned near at the bottom of water-bearing layer at the bottom of excavation of foundation pit face or in the range of excavation, water-bearing layer is relatively thin or there is local lens body, tube well dewatering is difficult to play its effect completely, is easily formed aquitard at part.Simultaneously for hypotonicity soil layer, the drainage coverage of dewatering well is little, and it is big that soil moisture in layer reduces difficulty, and corresponding pipe well spacing is less, will affect earth excavation, strengthens the problems such as pipe well protection difficulty.

Using and add the mode of vacuum and can improve drainage effect to a certain extent, but for hypotonicity soil layer, along with continuing of adding that vacuum draws water, the permeability of dewatering well periphery soil layer drastically diminishes, and affect dewatering well water yield, closely directly affects drainage efficiency.

Utility model content

For defect present in above-mentioned prior art, technical problem to be solved in the utility model is to provide a kind of gas drive base pit dewatering system that can improve hypotonicity soil layer drainage efficiency.

In order to solve above-mentioned technical problem, a kind of gas drive base pit dewatering system provided by the utility model, relate to civil engineering foundation pit, it is characterised in that: this system includes vacuum tube well unit, gas injection well unit；

Described vacuum tube well unit includes downcast well pipe, chimney filter, precipitation tube, filter, described downcast well pipe, chimney filter, precipitation tube is all vertically arranged between in the soil layer of foundation ditch, and chimney filter is positioned at below excavation of foundation pit face, the upper end mouth of pipe of chimney filter docks with the lower end mouth of pipe of downcast well pipe, the lower end mouth of pipe of chimney filter docks with the upper end mouth of pipe of precipitation tube, described filter envelopes chimney filter, the tube wall of precipitation tube and the bottom tube wall of downcast well pipe, the soil body of foundation ditch and downcast well pipe, chimney filter, an annular space it is formed with between the outer tube wall of precipitation tube, in this annular space, backfill filtrate forms filter material layer, and the backfill face capping of this filter material layer has clay sealing layer, immersible pump it is provided with in chimney filter, liquidometer, the upper end mouth of pipe of downcast well pipe is closed by a well lid, aspirating hole is offered on well lid；

Described gas injection well unit includes syringe, escape pipe, described syringe, escape pipe are all vertically arranged between in the soil layer of foundation ditch, the upper end mouth of pipe of syringe receives high-pressure air source, and equipped with the Pressure gauge for detecting intraductal atmospheric pressure on syringe, the upper end mouth of pipe of escape pipe docks with the lower end mouth of pipe of syringe, and the tube wall of escape pipe is breathed freely.

The gas drive base pit dewatering system that this utility model provides, gas injection well unit is utilized to inject gases at high pressure to drive subsoil water to collect excretion to downcast well pipe to soil mass of foundation pit, hypotonicity soil layer drainage efficiency can be improved, solve the problem that dewatering well is difficult to drainage at hypotonicity soil layer, locally water-bearing layer.

Accompanying drawing explanation

Fig. 1 is the structural representation of the gas drive base pit dewatering system of this utility model embodiment.

Detailed description of the invention

Illustrate embodiment of the present utility model is described in further detail below in conjunction with accompanying drawing; but the present embodiment is not limited to this utility model; every employing analog structure of the present utility model and similar change thereof; all should list protection domain of the present utility model in, the pause mark in this utility model all represents the relation of sum.

As it is shown in figure 1, a kind of gas drive base pit dewatering system that this utility model embodiment is provided, relate to civil engineering foundation pit, it is characterised in that: this system includes vacuum tube well unit, gas injection well unit；

nullDescribed vacuum tube well unit includes downcast well pipe 11、Chimney filter 12、Precipitation tube 13、Filter 14，Described downcast well pipe 11、Chimney filter 12、Precipitation tube 13 is all vertically arranged between in the soil layer of foundation ditch，And chimney filter 12 is positioned at below excavation of foundation pit face，The upper end mouth of pipe of chimney filter 12 docks with the lower end mouth of pipe of downcast well pipe 11，The lower end mouth of pipe of chimney filter 12 docks with the upper end mouth of pipe of precipitation tube 13，Described filter 14 envelopes chimney filter 12、The tube wall of precipitation tube 13 and the bottom tube wall of downcast well pipe 11，The soil body of foundation ditch and downcast well pipe 11、Chimney filter 12、An annular space it is formed with between the outer tube wall of precipitation tube 13，In this annular space, backfill filtrate forms filter material layer 17，And the backfill face capping of this filter material layer 17 has clay sealing layer 16，Immersible pump 15 it is provided with in chimney filter 12、Liquidometer 18，The upper end mouth of pipe of downcast well pipe 11 is closed by a well lid，Aspirating hole is offered on well lid；

Described gas injection well unit includes syringe 21, escape pipe 22, described syringe 21, escape pipe 22 are all vertically arranged between in the soil layer of foundation ditch, the upper end mouth of pipe of syringe 21 receives high-pressure air source, and equipped with the Pressure gauge 23 for detecting intraductal atmospheric pressure on syringe 21, the upper end mouth of pipe of escape pipe 22 docks with the lower end mouth of pipe of syringe 21, and the tube wall of escape pipe 22 is breathed freely.

This utility model embodiment is applicable to base pit dewatering, and its operation principle is as follows:

When implementing base pit dewatering, utilize gas injection well unit to inject gases at high pressure in soil mass of foundation pit, utilize gases at high pressure to promote the subsoil water of downcast well pipe 11 periphery to enter downcast well pipe 11；

When vacuum tube well unit carries out drainage to the soil layer of foundation ditch, vacuum pump is utilized to extract the gas in downcast well pipe 11 out, the water in downcast well pipe 11 extracted out by immersible pump 15, downcast well pipe 11 periphery is made to form precipitation funnel, gravitational water in soil layer constantly flows into downcast well pipe 11 under gravity and negative pressure of vacuum effect, owing to chimney filter 12 is positioned at below excavation of foundation pit face, may insure that the lasting maintenance of vacuum in downcast well pipe 11, filter material layer 17, clay sealing layer 16 and filter 14 can ensure that downcast well pipe 11 all has water guide function to the water-bearing layer at different depth, liquidometer 18 can ensure that immersible pump 15 can use under water level always, guarantee the service life of immersible pump 15, also can control the water level in downcast well pipe 11 simultaneously.

This utility model embodiment can be according to the difference on stratum and operation duration, the gas of different pressures can be added flexibly for Different Strata, gas pressure will be transmitted on subsoil water in the saturated condition, and then promote the flowing of subsoil water, under unsaturated state, gas flowing in hole also will accelerate the flowing of subsoil water.

Claims (1)

1. a gas drive base pit dewatering system, relates to civil engineering foundation pit, it is characterised in that: this system includes vacuum tube well unit, gas injection well unit；

Described vacuum tube well unit includes downcast well pipe, chimney filter, precipitation tube, filter, described downcast well pipe, chimney filter, precipitation tube is all vertically arranged between in the soil layer of foundation ditch, and chimney filter is positioned at below excavation of foundation pit face, the upper end mouth of pipe of chimney filter docks with the lower end mouth of pipe of downcast well pipe, the lower end mouth of pipe of chimney filter docks with the upper end mouth of pipe of precipitation tube, described filter envelopes chimney filter, the tube wall of precipitation tube and the bottom tube wall of downcast well pipe, the soil body of foundation ditch and downcast well pipe, chimney filter, an annular space it is formed with between the outer tube wall of precipitation tube, in this annular space, backfill filtrate forms filter material layer, and the backfill face capping of this filter material layer has clay sealing layer, immersible pump it is provided with in chimney filter, liquidometer, the upper end mouth of pipe of downcast well pipe is closed by a well lid, aspirating hole is offered on well lid；

Described gas injection well unit includes syringe, escape pipe, described syringe, escape pipe are all vertically arranged between in the soil layer of foundation ditch, the upper end mouth of pipe of syringe receives high-pressure air source, and equipped with the Pressure gauge for detecting intraductal atmospheric pressure on syringe, the upper end mouth of pipe of escape pipe docks with the lower end mouth of pipe of syringe, and the tube wall of escape pipe is breathed freely.