Method and device for monitoring subsidence of deep soil layer in soft soil layer

Abstract

The invention provides a method and device for monitoring the layered subsidence of deep soil in soft soil stratum. The signal probe; the monitoring control module includes a liquid injection leveling device, a probe retractable device and a measuring pipe joint sleeve; the probe includes a signal receiving element and a hydraulic measuring element. The settlement mark is pre-set in the surrounding formation of the measuring tube before the monitoring operation, and the liquid leveling device is used to inject liquid into the measuring tube and level the liquid level reference. And the processing module collects and processes the data measured by the probe to obtain the settlement situation of the monitoring points of the vertical stratification of the deep soil in the soft soil layer. The invention can greatly reduce the influence of the rigidity of the measuring tube itself on the monitoring accuracy; and can realize single-hole multi-point automatic rapid measurement, and improve the monitoring accuracy and efficiency of soil layered settlement.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering monitoring, and in particular relates to a method and a device for monitoring the layered subsidence of deep soil in soft soil layers. Background technique [0002] During the construction of rock and earth underground engineering, in order to ensure the safety of the project itself and effectively control the impact on the surrounding environment, it is necessary to grasp the deformation and trend of the surrounding stratum medium in time. Through settlement monitoring, the important data index of stratum settlement can be collected in real time. As the depth of underground space development continues to increase, the use of relatively simple surface settlement monitoring can no longer directly reflect the soil deformation around the construction work area. The implementation of deep soil settlement monitoring can provide more effective environmental impact quantitative criteria f...

AI Technical Summary

Problems solved by technology

[0005] However, the deep marking point level has the following defects: 1) a borehole can only arrange one deep marking point, and one deep marking point can only complete the subsidence monitoring of a single depth formation, and several measuring points then need several boreholes, which cannot be formed if there are too few arrangements. Effective monitoring, too many arrangements will greatly affect the construction work space; 2) According to the monitoring principle of this method, the measurement accuracy must be guaranteed under the condition of small lateral displacement of the sleeve, which is common in underground engineering in soft soil areas. Lack of applicability for large lateral deformations

[0007] However, the magnetic ring sedimentation instrument has the following defects: 1) the magnetic ring is sleeved on the conduit, and the conduit has a certain restraint effect on the displacement of the magnetic ring. The absolute synchronous deformation between the magnetic ring and the formation cannot be guaranteed, which leads to measurement failure; 2) The conduit and the gap filling medium within a certain range around the pipe form a "composite micropile" with a larger stiffness than the original soil. ”, the existence of the “mini-pile” effect further causes the deformation of the magnetic ring and cannot accurately reflect the displacement of the surrounding strata; 3) There is a certain range in the up and down sliding position of the magnetic ring, which determines its limited range. When the magnetic ring reaches The joint cannot continue to slide, resulting in the failure of subsequent measurements; 4) The conduit will also be deformed to a certain extent after the ground displacement occurs. At this time, a probe with a length mark is used to measure the settlement in the bend. In fact, it is the length of the axis curve of the elbow, not the real absolute level height; 5) The accuracy of reading and measurement depends on how to determine the starting position of pronunciation or indication, which is mostly affected by the subjective judgment of the operator; 6 ) During the installation process, it is difficult to ensure that the hole wall gap between the two magnetic rings is filled tightly. This situation can easily affect the accuracy of the measuring point or even be scrapped directly.

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