A Test Device for Measuring Extrusion Deformation of Tunnel Face

Abstract

The invention relates to a test device for measuring the extrusion deformation of the face of a tunnel. The lateral extrusion displacement of the tunnel monitoring section is converted into the displacement of the grating scale and measured. The device includes: a model test box: the test box is a top opening The box is filled with model soil, and there is an excavation experiment opening at the lower part of the side wall of the box; displacement measurement device: including extrusion deformation induction head, steel wire and grating scale displacement sensor connected in sequence; displacement transmission channel: set It is arranged outside the steel wire to avoid the interference of the model soil on the steel wire, including horizontal plastic thin pipes, PVC elbow joints and vertical PVC pipes that are buried in the model soil and connected in sequence. The vertical PVC pipes The upper end protrudes from the model soil. Compared with the prior art, the invention has the advantages of clear and effective measurement form, simple manufacture, low cost, high measurement accuracy and less space occupation.

Description

technical field [0001] The invention relates to a measurement test device, in particular to a test device for measuring extrusion deformation of tunnel face. Background technique [0002] Such as Figure 4 As shown, the figure is a schematic diagram of an invention patent with the application number CN202255259U. In the figure: 1. model body, 2. model material, 3. tunnel profile, 4. multi-point displacement meter, 5. jack and pressure plate, 6. reverse Force beam, 13, grating ruler. The device connects the pentagonal steel sheet to the vertical grating scale through a change of direction of the steel wire rope. The steel wire passes through multiple sliders. In the test, an L-shaped polytetrafluoroethylene tube is used as a protective channel. The device has the following obvious defects: (1) The key instrument for measurement-the grating ruler is vertically installed, and the measurement of the grating ruler is to measure the change of displacement by indicating the positi...

AI Technical Summary

Problems solved by technology

The device has the following obvious defects: (1) The key instrument for measurement-the grating ruler is vertically installed, and the measurement of the grating ruler is to measure the change of displacement by indicating the position of the grating. Greatly affects the movement of the indicating grating, which leads to a serious decrease in the accuracy and reliability of the measurement results

(2) In addition to contacting the pulley, the steel wire rope also contacts multiple sliders during the transmission displacement process. Contacting multiple sliders increases the friction probability during the transmission process and seriously affects the monitoring data.

(3) The pentagonal miniature measuring anchor head has a large extension range and has a strong anchoring effect on the excavation surface soil, making extrusion deformation more difficult

(4) The L-shaped channel used in the test, the transverse PTFE tube has a reinforcement effect on the soil in front of the excavation face, which affects the extrusion deformation of the excavation face

(5) When the wire rope extends out of the L-shaped lower channel, there is no protection or anti-friction measures around the wire rope, so that the wire rope is subject to greater resistance when moving, which seriously affects the measurement results

(6) The design of the device is more complicated, and the implementation is more time-consuming and laborious

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