Precipitation technology of integrated directional vacuum well-point pipe

Abstract

The invention discloses a precipitation technology of an integrated directional vacuum well-point pipe. The precipitation technology comprises the steps that first, the initial sinking point of the vacuum well-point tube is determined; second, the sinking dip angle of the vacuum well-point pipe is determined, and the vacuum well-point pipe is arranged in place; third, the vacuum well-point pipe ismounted in a punched hole; fourth, vacuumizing and precipitation are conducted; fifth, a first layer of earthwork is excavated; sixth, a next layer of earthwork is excavated; and the sixth step is conducted repeatedly until all the preset layers of earthworks are excavated. According to the precipitation technology, the well-point tube is obliquely sunk along an excavation slope, a water inlet ofthe well-point pipe is close to the lower middle portion of an excavation face, the precipitation efficiency is improved, directional precipitation is achieved, and large-range precipitation of underground water outside a foundation pit is prevented. High-cost input of secondary well points, pipe well points, spurting well points and the like are not needed for well point pipe edge excavation andside sinking, and deep precipitation can be achieved. The precipitation cost is low, and the precipitation technology is suitable for large-scale application and popularization.

Description

technical field [0001] The invention relates to the field of building construction, in particular to a vacuum well point pipe and a corresponding dewatering process. Background technique [0002] In the construction of generally deep underground projects, most of the construction methods of grading or supporting excavation are adopted. When the construction depth is below the groundwater level, the foundation pit often encounters underground water gushing or quicksand invasion. Therefore, it is necessary to use Artificially lowering the groundwater table. [0003] A large amount of groundwater extraction will cause ground subsidence around the site, deformation of buildings, and environmental degradation of water and soil resources. With the enhancement of the government's awareness of environmental protection in recent years, the awareness of protecting groundwater resources has been continuously strengthened, and a series of measures to limit pumping and discharge have be...

AI Technical Summary

Problems solved by technology

[0008] One is that after the hole is formed, it is necessary to pull out the flushing gun controlled by the crane, then put it into the well point device by the crane, and finally fill the hole with sand, so that the interval between the formation of the well hole and the filling of sand must be relatively long. Long, which will easily cause the soil on the hole wall to collapse, silt or partially silt the filter head of the lower part of the well point device for pumping groundwater, which will directly affect its function of pumping groundwater, thereby seriously affecting the quality of the precipitation project

This kind of condition that affects the quality of the dewatering project due to the collapse of the hole wall due to the long flushing and sinking time is especially serious in the soil conditions of muddy silt and silty fine sand and in the construction of secondary light well point dewatering projects.

[0009] Second, because the flushing guns used for flushing caisson holes are larger in diameter, length and weight than vacuum well point pipes, therefore, the punching operation needs to be operated by a crane, which takes up a large amount of dewatering engineering. Construction costs

[0010] 3. For soft soil layers, especially muddy soil layers, the water outlet effect and survival rate of the vacuum well point pipe are not good, because the water inlet hole of the filter head is often easily blocked by impermeable silt, and a "dead pipe" is formed in severe cases.

[0011] 4. The burial of traditional vacuum wellpoint pipes requires the construction of wellpoint holes in advance. The drainage channel is formed by the coarse sand poured into the soil after the vacuum wellpoint pipes are buried. The construction speed is slow and the cost of materials is high; It is difficult to control the amount of coarse sand poured in, and it is difficult to form a smooth drainage channel, resulting in poor precipitation effect

Since it is necessary to adopt multi-level precipitation to achieve the desired effect, a large amount of equipment and electric power are wasted

[0013] 6. The traditional well point pipe is installed on the outside of the working pit (foundation pit). The water inlet of the well point pipe is far away from the excavation surface, and the precipitation efficiency is low; The large-scale reduction of groundwater outside the foundation pit caused the uneven settlement of the ground outside the foundation pit, causing a series of environmental and safety problems

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