Instrument and method for monitoring cavity beneath tunnel passing through ground fissure zone

Abstract

The invention provides an instrument and method for monitoring a cavity beneath a tunnel passing through a ground fissure zone. The monitoring instrument comprises a cloud deck close to a ground fissure at the bottom of the tunnel, and a laser range finder on the cloud deck, wherein connecting pieces are pre-buried in the central position of the bottom of a subsection of the tunnel passing through the ground fissure, the cloud deck is installed on the connecting pieces, and then, the laser range finder is arranged on the cloud deck; and data control software in a data processing system is utilized to control the laser range finder to automatically acquire cavity monitoring data at fixed time. The monitoring instrument utilizes the range finding principle of the laser range finder, is simple in structure, easy to operate and low in cost, and can monitor the cavity area in real time and obtain the variation conditions of the cavity area timely.

Description

technical field [0001] The invention belongs to the technical field of void monitoring in ground fissures, and in particular relates to a void monitoring instrument and a monitoring method at the bottom of tunnels passing through ground fissures. Background technique [0002] Ground fissures are a common geological hazard found in many countries around the world, such as China, the United States, Turkey, Thailand, and Libya. The distribution of ground fissures in my country is very extensive. With the acceleration of urbanization, the development of ground fissures has a tendency to expand in scope and aggravate the harm. [0003] Since the subway is a long-line project, the ground fissures cannot be avoided by conventional avoidance methods, so it is required that the subway tunnels must pass through the ground fissures safely. Existing studies have found that when the ground fissures are active, because the subway tunnel crosses the ground fissures, with the settlement of...

AI Technical Summary

Problems solved by technology

[0007] However, due to the complexity of the medium in the void zone, the velocity of radar waves in the void zone cannot be accurately determined; secondly, the characteristics of the reflected wave at the second interface are difficult to confirm, resulting in the height of the void zone cannot be accurately quantified

Ground radar cannot perform real-time monitoring, and the formation of the void range at the bottom of the tunnel cannot be predicted in time, and the application of radar is cumbersome and expensive

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