Multipoint coal and rock mass stress real-time monitoring device and method
A multipoint coal and rock mass stress real-time monitoring device is provided. The device is composed of a plurality of capsule pressure sensors ( 1 ), connection rods ( 2 ), three-way valves ( 3 ), a multichannel monitor ( 4 ), a multichannel control valve ( 5 ), first high-pressure oil pipes ( 6 ), second high-pressure oil pipes ( 7 ), third high-pressure oil pipes ( 8 ), a four high-pressure oil pipe ( 9 ), a high-pressure oil pump ( 10 ) and monitoring substations ( 11 ). A multipoint coal and rock mass stress real-time monitoring method is also provided.
1. A multipoint coal and rock mass stress real-time monitoring method utilizing a multipoint coal and rock mass stress real-time monitoring device, the device comprising: a plurality of capsule pressure sensors, connection rods, three-way valves, a multi-channel monitor, a multi-channel control valve, first high-pressure oil pipes, second high-pressure oil pipes, third high-pressure oil pipes, fourth high-pressure oil pipes, a high-pressure oil pump and monitoring substations, wherein the capsule pressure sensors are connected serially via the connecting rods, and the connecting rods are in the same quantity as the capsule pressure sensors; each capsule pressure sensor is connected with a first high-pressure oil pipe, which runs through a connecting rod and is connected to a three-way valve, and connected to the multi-channel monitor and the multi-channel control valve via the three-way valves, and the multi-channel control valve is connected to the high-pressure oil pump,
the method comprising the following steps:
a) determining a monitoring area and positions of holes to be drilled according to monitoring demand, and determining a drilling depth according to the number of monitoring points arranged in the holes to be drilled and monitoring positions;
b) drilling holes in a coal and rock mass to a specified depth;
c) determining the length of each connecting rod according to a stress monitoring scheme, connecting the capsule pressure sensors serially via the connecting rods, running the first high-pressure oil pipes connected with the capsule pressure sensors through the connecting rods and leading out of the drilled holes, and putting the capsule pressure sensors into the drilled holes to predetermined positions;
d) connecting the second high-pressure oil pipes and the third high-pressure oil pipes led out of the drilled holes to the multi-channel monitor and the multi-channel control valve via the three-way valves respectively, and connecting the multi-channel control valve to the high-pressure oil pump;
e) injecting oil through the high-pressure oil pump into the capsule pressure sensors via the multi-channel control valve and holding the pressure to increase steadily; when the pressure reaches a preset pressure and remains stable, stopping oil injection, closing the three-way valves, removing the multi-channel control valve and the high-pressure oil pump, and sealing oil injection holes with a plug; and
f) sensing the stress in the coal and rock mass with the capsule pressure sensors, synchronously acquiring, converting, storing, and displaying the data with the multi-channel monitor, or transmitting the data to a remote monitoring center through monitoring substations, and determining the real-time stress distribution and stress variation at different positions in the drilled hole by analyzing the monitoring data.