Self entering type surrounding rock pore water pressure sensing device

Abstract

The invention discloses a self entering type surrounding rock pore water pressure sensing device, which comprises a head end drilling section, a strengthened water penetration section, a pressure sensing section and a tail end fastening section, which are connected in sequence from the head to the tail. The head end drilling section comprises a drilling bit at front part and a rod body at back part that are mutually connected; the strengthened water penetration section includes an outer water penetration tube with a plurality of permeable holes on the tube wall and a filtering layer arranged in the outer water tube; the pressure sensing section comprises a sensor outer tube with screws arranged on the outer wall; the sensor outer tube is provided with a pressure bearing cavity and a pressure sensing element; the tail end fastening section comprises is provided on the outer wall with a fastening outer tube with screws and the nuts sheathed on the fastening outer tube. According to the invention, a head end drilling section, a strengthened water penetration section, a pressure sensing section with a pressure detecting function and a tail end fastening section with a fastening connection function are integrated into one, which can, on one hand, guarantee the safety of a sensor signal line and can, on the other hand, guarantee the accuracy and effectiveness of water pressure tests.

Description

technical field [0001] The invention relates to a surrounding rock pore water pressure sensing device, in particular to a self-propelled surrounding rock pore water pressure sensing device, which belongs to the field of tunnel and underground engineering monitoring. Background technique [0002] The advantages of shield tunneling in terms of construction safety, speed and economy make it more and more used in urban water-rich and weak strata, especially in underwater tunnel projects in rivers, lakes, rivers and seas. Accurately consider the impact of water pressure on the safety of tunnel segment lining structures. Influence is increasingly necessary. Therefore, real-time and accurate monitoring of the pore water pressure of the surrounding rock behind the lining wall is required. [0003] At present, the pore water pressure test of the surrounding rock behind the shield tunnel wall mainly adopts the embedded method, that is, before the segment concrete is poured, the pore ...

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Problems solved by technology

[0004] However, the embedded water pressure sensor has the following problems: first, when the surrounding rock pore water pressure sensor is pre-embedded, the concrete vibration is easy to change its position and direction, and at the same time, the concrete vibration is also easy to damage the sensor wire, resulting in sensor failure; Even if the surrounding rock pore water pressure sensor is correctly installed in place, due to the cover of the shield synchronous grouting slurry on the outside of the segment, the hardened slurry will form a hard shell on the outside of the sensor, hindering the connection between the groundwater in the surrounding rock and the outer surface of the sensor. Connectivity, resulting in serious inaccurate or even invalid sensor reading data

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