CN205444216U - Depth well foundation pit dewatering system on compound stratum of large -scale foundation ditch - Google Patents

Abstract

The invention relates to a deep and shallow well foundation pit dewatering system for a large-scale foundation pit composite stratum, which relates to the technical field of civil construction and solves the technical problems of improving the dewatering effect and shortening the dewatering cycle. The system includes at least one deep vacuum tube well unit and a plurality of shallow downwater tube well units, the layout density of each deep vacuum tube well unit is less than that of each shallow downwater tube well unit; Perform slow dehydration, and use the shallow downwater tube well unit and the deep vacuum tube well unit to implement rapid dehydration on the shallow soil layer of the foundation pit. The system provided by the utility model is suitable for the dewatering operation of large-scale foundation pit composite strata.

Description

Deep and shallow well foundation pit dewatering system in large foundation pit compound stratum

technical field

The utility model relates to civil construction technology, in particular to a technology of a deep and shallow well foundation pit dewatering system in a large foundation pit composite stratum.

Background technique

With the development of urban underground space, more and more large-scale deep foundation pits are being constructed, and the control of groundwater during construction is becoming more and more important. The shear strength and the stability of the foundation pit are convenient for earthwork excavation and construction in the foundation pit. Generally, draining tube wells are used for dewatering.

At present, for dewatering and precipitation, the drainage tube wells are generally arranged uniformly according to the area, and the depth is uniformly considered as 5-6m below the excavation surface, that is, the difference of the soil layer in the section within the excavation range is not considered, and the soil of each layer is not considered. Due to the difference in the excavation construction period, considering the convenience of construction and economical efficiency, the spacing of ordinary dewatering wells is insufficient for the dewatering density of the shallow soil layer, while the distance between the deep soil layer is relatively large, and there is a problem of precipitation. The defects of poor effect and long precipitation cycle. At the same time, the current layout of dewatering wells does not take into account the differences in formation, especially the disposal of local interlayers. For large-scale foundation pits, due to the large area of the foundation pit, the infiltration and discharge of surface water during rainfall is a relatively serious construction problem. Due to cycle and economic issues, there are few corresponding measures for such large-scale foundation pits.

Utility model content

In view of the above-mentioned defects in the prior art, the technical problem to be solved by the utility model is to provide a deep and shallow well foundation pit dewatering system with good dewatering effect and closely combined with the excavation conditions of the foundation pit in the complex stratum of the large foundation pit.

In order to solve the above technical problems, the utility model provides a deep and shallow well foundation pit dewatering system for a large foundation pit composite stratum, which relates to a civil foundation pit, and is characterized in that: the system includes at least one deep vacuum tube well unit, and several layer downwater tube well unit, the quantity of the shallow downwater tube well unit is more than the number of deep vacuum tube well units, and the layout density of each deep vacuum tube well unit is less than the layout density of each shallow downwater tube well unit;

The deep vacuum tube well unit includes deep dewatering well pipes, filter pipes, sedimentation pipes, and spacers. The deep dewatering well pipes, filter pipes, and sedimentation pipes are all vertically placed in the soil layer of the foundation pit, and the filter pipe is located in the foundation pit. Under the excavation surface, the upper nozzle of the filter pipe is connected with the lower nozzle of the deep-layer dewatering well pipe, and the lower nozzle of the filter pipe is connected with the upper nozzle of the sedimentation pipe. The pipe wall and the lower pipe wall of the deep dewatering well pipe, the outer pipe wall of the deep dewatering well pipe, filter pipe, and sedimentation pipe are covered with the first filter material layer, and the backfill surface of the first filter material layer is covered with a clay seal. In the interlayer, there are deep submersible pumps and liquid level gauges in the filter pipe, and the upper end nozzle of the deep dewatering well pipe is closed by a well cover, and the well cover is provided with air extraction holes;

The shallow dewatering well unit includes a shallow dewatering well pipe, the shallow dewatering well pipe is vertically placed in the soil layer of the foundation pit, and the bottom end of the shallow dewatering well pipe is higher than the bottom end of the deep dewatering well pipe, The upper end of the shallow dewatering well pipe is higher than the ground to prevent surface water from entering the shallow dewatering well pipe directly. The shallow dewatering well pipe is equipped with a shallow submersible pump, and the lower pipe section of the shallow dewatering well pipe is equipped with a radial Through the filter holes, the outer pipe wall of the shallow downwater well pipe is covered with a second filter material layer, and the backfill surface of the second filter material layer is lower than the ground.

The deep and shallow well foundation pit dewatering system of the large-scale foundation pit composite stratum provided by the utility model, through the cooperative dewatering of densely distributed shallow dewatering tube well units and sparsely distributed deep vacuum tube well units, the shallow soil layer can be quickly drained, and the deep part The soil layer is slowly drained, which not only ensures the effect of precipitation, but also closely combines the excavation conditions of the foundation pit, reduces the number of tube wells to be protected, and solves the problem of the correspondence between the excavation period of the foundation pit and the precipitation of the foundation pit in terms of time and space. And the dehydration efficiency of the shallow soil layer of the large foundation pit.

Description of drawings

Fig. 1 is a structural schematic diagram of a deep and shallow well foundation pit dewatering system of a large foundation pit composite stratum according to an embodiment of the present invention.

detailed description

The embodiments of the present utility model are described in further detail below in conjunction with the accompanying drawings, but the present embodiments are not intended to limit the present utility model. All similar structures and similar changes of the utility model should be included in the protection of the utility model. Scope, the comma in the utility model all represents and the relation.

As shown in Figure 1, the deep and shallow well foundation pit dewatering system of a large foundation pit composite stratum provided by the embodiment of the utility model relates to a civil foundation pit, and is characterized in that the system includes at least one deep vacuum tube well unit, and at most shallow downfall tube well units, the quantity of the shallow downfall tube well units is more than the number of deep vacuum tube well units, and the layout density of each deep vacuum tube well unit is less than the layout density of each shallow downwater tube well unit;

The deep vacuum tube well unit includes a deep dewatering well pipe 11, a filter pipe 12, a sedimentation pipe 13, and a screen 14, and the deep dewatering well pipe 11, filter pipe 12, and sedimentation pipe 13 are all vertically placed in the soil layer of the foundation pit , and the filter pipe 12 is located below the excavation surface of the foundation pit, the upper end nozzle of the filter pipe 12 is docked with the lower end nozzle of the deep dewatering well pipe 11, and the lower end nozzle of the filter pipe 12 is docked with the upper end nozzle of the sedimentation pipe 13, so The spacer 14 covers the pipe wall of the filter pipe 12, the sedimentation pipe 13 and the lower pipe wall of the deep dewatering well pipe 11. An annular space is formed between the walls, and the filter material is backfilled in the annular space to form the first filter material layer 17, and the backfill surface of the first filter material layer 17 is covered with a clay sealing layer 16, and a deep layer is arranged in the filter pipe 12. The submersible pump 15, the liquid level gauge 18, and the upper nozzle of the deep dewatering well pipe 11 are closed by a well cover, and the well cover is provided with an air extraction hole;

The shallow downwater well unit includes a shallow downwell pipe 21, which is vertically placed in the soil layer of the foundation pit, and the bottom end of the shallow downwell pipe 21 is higher than the deep downwell pipe 11 The bottom end of the shallow dewatering well pipe 21 is higher than the ground, to prevent surface water from directly entering the shallow dewatering well pipe 21, the shallow dewatering well pipe 21 is provided with a shallow submersible pump 22, and the shallow dewatering well The lower pipe section of the pipe 21 is provided with a radially penetrating filter hole 211, and an annular space is formed between the soil body of the foundation pit and the outer pipe wall of the shallow dewatering well pipe 21, and the filter material is backfilled in the annular space to form a second filter. material layer 23, and the backfill surface of the second filter material layer 23 is lower than the ground to gather surface water such as rainwater, so that the surface water enters the shallow dewatering well pipe 21 after being filtered by the second filter material layer 23, ensuring that the pumping Water quality of external drainage.

The dewatering method of the deep and shallow well foundation pit dewatering system provided by the embodiment of the utility model is characterized in that: each deep vacuum tube well unit is used to slowly dry the deep soil layer of the foundation pit, and each The shallow downfall tube well unit and each deep vacuum tube well unit perform quick dehydration on the shallow soil layer of the foundation pit; and after the dewatering of the shallow soil layer of the foundation pit Pull out for subsequent construction.

When the shallow dewatering well unit drains the deep soil layer of the foundation pit, the shallow submersible pump 22 pumps out the collected water body in the shallow dewatering well pipe 21, and the collected water body in the shallow dewatering well pipe 21 includes the shallow The water in the lower strata and the open drainage collected during the rain, during the pumping process of the shallow submersible pump 22, the gravity water in the shallow stratum of the foundation pit will continuously flow into the shallow dewatering well tube well under the action of gravity;

When the deep vacuum tube well unit drains the deep soil layer of the foundation pit, the vacuum pump is used to extract the gas in the deep dewatering well pipe 11, and the upper deep submersible pump 15 pumps out the water in the deep dewatering well pipe 11, so that the surrounding area of the deep dewatering well pipe 11 A dewatering funnel is formed, and the gravity water in the soil layer continuously flows into the deep dewatering well pipe 11 under the action of gravity and vacuum negative pressure. Since the filter pipe 12 is located below the excavation surface of the foundation pit, the vacuum degree in the deep dewatering well pipe 11 can be ensured. Sustainability, the first filter material layer 17, the clay sealing layer 16 and the screen 14 can ensure that the deep dewatering well pipe 11 has the function of conducting water to the aquifers at different depths, and the liquid level gauge 18 can ensure that the deep submersible pump 15 Can be used under the water level all the time, guarantee the service life of deep submersible pump 15, also can control the water level in the deep downwater well pipe 11 simultaneously.

Claims (1)

1. the depth well base pit dewatering system of a Large Foundation Pit compound stratum, relate to civil engineering foundation pit, it is characterized in that: this system includes at least one deep vacuum pipe well unit, and to multiple shallow-layer precipitation pipe well unit, the quantity of described shallow-layer precipitation pipe well unit is more than the quantity of deep vacuum pipe well unit, and the layout density of each deep vacuum pipe well unit is less than the layout density of each shallow-layer precipitation pipe well unit；

Described deep vacuum pipe well unit includes deep layer downcast well pipe, chimney filter, precipitation tube, filter, described deep layer 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 deep layer 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 deep layer downcast well pipe, deep layer downcast well pipe, chimney filter, the outer tube wall of precipitation tube is coated with the first filter material layer, and the backfill face capping of this first filter material layer has clay sealing layer, deep layer immersible pump it is provided with in chimney filter, liquidometer, the upper end mouth of pipe of deep layer downcast well pipe is closed by a well lid, aspirating hole is offered on well lid；

Described shallow-layer precipitation pipe well unit includes shallow-layer downcast well pipe, described shallow-layer downcast well pipe is vertically arranged between in the soil layer of foundation ditch, and the bottom of shallow-layer downcast well pipe is higher than the bottom of deep layer downcast well pipe, the upper end mouth of pipe of shallow-layer downcast well pipe is above the ground level, to prevent surface water to be directly entered shallow-layer downcast well pipe, shallow-layer immersible pump it is provided with in shallow-layer downcast well pipe, the most through filter opening is offered in the lower tubular section of shallow-layer downcast well pipe, the outer tube wall of shallow-layer downcast well pipe is coated with the second filter material layer, and the backfill face of this second filter material layer is less than ground.