HomeCombined method of well point precipitation and vacuum preloading
Release time：Jul 24,2023
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Combined method of well point precipitation and vacuum preloading
The well point precipitation method is a mature technology that involves setting well points in the foundation, allowing free water in the foundation to collect under the action of gravity into the well points, forming a well point precipitation funnel in the foundation soil. As the water in the well is continuously pumped out, the water around the well gradually collects into the well, and the groundwater level decreases accordingly. As groundwater is discharged, the effective stress between soil particles increases, and the foundation soil is reinforced as a result.
According to the working principle of well point precipitation, especially for deep groundwater, the introduction of well point precipitation in vacuum preloading can compensate for the shortcomings of traditional vacuum preloading technology. Therefore, the reinforcement method of vacuum preloading combined with well point precipitation, such as using light well points, uses the same pumping system to apply vacuum to the foundation soil through both the well points and plastic drainage boards.
The pressure difference (vacuum degree) generated by vacuum pumping is connected to the light well point through a mud water separator. During precipitation, negative pressure is generated at the interface of the sand well, which acts on the foundation soil; The pre embedded plastic drainage board is connected to the sand well through a natural buried sand layer, thereby creating a negative pressure effect in the deep soil. At the same time, due to the additional pressure formed by vacuum negative pressure, precipitation, and ground loading, the pore water pressure in the deep foundation increases, causing the deep pores to flow along the vertical channel provided by the plastic drainage board in the shallow layer, which is discharged by a light well point system. A grouting curtain is set up around the precipitation area to cut off water supply.
The combination of well point precipitation and vacuum preloading technology can improve the properties of soil, increase its shear strength, and enhance its stability; It can reduce the horizontal displacement and post construction settlement of soil, especially suitable for soft soil embankments with permeable thin sand layers in the soil. It has met the design requirements and greatly shortened the construction period.
