Direct-adhesive Hole Wall Strain Measuring Instrument

Abstract

The present invention relates to the technical field of devices for measuring strain and ground pressure in geotechnical and mine engineering, and concretely discloses a direct adhering type wall hole strain measuring device. The device comprises a device body and an installation rod for pushing the device body; the device body comprises a measuring line, and a hole sealing seat, a connection tube, a base and an adhesive receiving tube which are connected in sequence; the hole sealing seat is provided with a first liquid expansion sac; a second liquid expansion sac surrounding a second liquid guide groove and covering part of an outer surface of the part of the adhesive receiving tube; a blocking ring is disposed at an outer surface of the hole sealing seat; a first liquid inlet and a second liquid inlet are communicated with each other through the connection tube; a gap used for allowing an adhesive liquid to be injected into a measured drill hole is disposed between a right end of the hole sealing seat and a left end of the base; a piston rod sleeves a right end of the adhesive receiving tube in a sliding manner; and a plurality of strain rosettes of the measuring line are disposed at the outer surface of the second liquid expansion sac. The direct adhering type wall hole strain measuring device has the advantages that strain gages and the hole wall directly contact and the installation survival rate is high.

Description

technical field [0001] The invention relates to the technical field of devices used for measuring strain and ground pressure in geotechnical and mining engineering, in particular to a direct-adhesive hole wall strain measuring instrument. Background technique [0002] Hole wall strain is the core indicator for in-situ rock stress testing, mining dynamic pressure testing, rockburst monitoring, and coal and gas outburst monitoring, and is extremely important for rock soil and mine construction. [0003] At present, the strain and stress measurement devices with the same function include hollow inclusions and borehole strain gauges. The hollow inclusions include three types: 9-pack strain gauges, 13-pack strain gauges and 12-pack strain gauges. Before installation, measure the strain The strain gauge is pre-embedded outside the hollow hose, and the installation gap between the hollow hose and the hole wall is filled with resin for the second time during installation. Because th...

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Problems solved by technology

[0003] At present, the strain and stress measurement devices with the same function include hollow inclusions and borehole strain gauges. The hollow inclusions include three types of strain gauges, 13 strain gauges and 12 strain gauges. Before installation, measure the strain The strain gauge is pre-embedded outside the hollow hose, and the installation gap between the hollow hose and the hole wall is filled with resin for the second time during installation. Because the strain gauge and the hole wall are not in direct contact, the influence of the spacer resin must be considered in the stress calculation. In order to avoid the calculation difficulty and measurement error; when installing, use a rubber ring to snap into the hole to seal the resin. If the hole wall seeps water or is too rough, it will form a potting cavity, and even the resin will be lost. The installation survival rate is not high.

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