Compartment Camera Type Groundwater Level Measuring Device and Its Working Method

Abstract

A compartment camera shooting type vacuum precompressed underground water level measuring device and a working method thereof; the measuring device comprises a water level tube and a measuring unit; the water level tube buried underground is wrapped by a nonwoven earthwork cloth; the features are that the water level tube is vertically divided by a transparent material isolation plate to form two semicolumn spaces, wherein one half is an up-down connected waterproof tube cavity, and the other half is a permeable filter tube cavity; the filter tube cavity is divided by a semicircle filter tube cavity isolation plate so as to form a row of vertical small compartments mutually blocked; the measuring unit comprises a scale data line and a camera on the end portion; the camera moves up and down along the scale data line in the waterproof tube cavity, thus observing the water level in the filter tube cavity. The method and device can remove the sealing effect caused by an existing vacuum precompressed underground water level measuring device sealed tube section and the vertical water lift effect caused by the up-down connected filter tube section; the tube surrounding negative pressure environment cannot be changed in the measuring process, thus satisfying the vacuum precompressed underground water level measuring basic requirements.

Description

technical field [0001] The invention relates to the field of on-site testing of groundwater levels, in particular to a compartment camera-type groundwater level measuring device for testing groundwater levels in vacuum preloading soft foundation treatment. The invention also relates to the method of operation of such a measuring device. Background technique [0002] Vacuum drainage preloading method is an effective soft foundation treatment technology, which has been widely used in recent years and has been continuously improved in combination with new processes and methods. The change law of groundwater level under negative pressure environment is a basic problem in the theoretical research of vacuum preloading. Its importance lies in: ① The change of groundwater level is a necessary condition for the study of vacuum preloading reinforcement mechanism. area distribution, thereby changing the effective stress distribution and affecting the effect of vacuum preloading reinfo...

AI Technical Summary

Problems solved by technology

The existing vacuum preloaded groundwater level measuring pipes are all hollow inside, and are composed of impermeable pipe sections and filter pipe sections. However, the underground water level of the site treated by vacuum preloading method is usually shallow. If the distribution range of the filter pipe sections is small (buried If the depth is too large), the exchange of fluid inside and outside the pipe will be slow, and the change of water level in the pipe will obviously lag behind the water level in the soil. At the same time, the sealing space at the top of the water level pipe is also prone to airtight effect; while the water level pipe is hollow and connected up and down, it will make the range of filter pipe section memory In the case of vertical water lifting, and the larger the distribution range of the filter pipe section and the more severe the vacuum degree changes, the water level in the pipe is easier to be higher than the water level in the soil under the vertical water lifting effect.

At present, the method of adjusting the distribution of filter pipe sections in engineering can not eliminate the above-mentioned airtight effect and vertical water lifting effect. The water level pipe structure is placed in the foundation under a negative pressure environment. The water level in the pipe cannot accurately represent the water level in the soil. Even if the water level in the pipe is accurately measured, it is not necessarily the groundwater level value of the vacuum preloaded foundation treatment.

However, most of the existing vacuum preloading groundwater level measurement improvement schemes ignore the above problems, and pay little attention to whether the water level in the water level pipe can represent the real groundwater level.

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