Method and system for predicting blasting vibration inside surrounding rocks in deep buried tunnels

A method for predicting blasting vibration inside surrounding rocks in deep buried tunnels, comprising:

• horizontally drilling a plurality of test boreholes from a pilot tunnel into the surrounding rocks, and mounting blasting vibration sensors in sequence at a borehole bottom of each test borehole, wherein the plurality of test boreholes using a tunnel face of a subsequent tunnel as a symmetry plane are uniformly distributed in a region in front of and behind the tunnel face;
• performing blasting on the subsequent tunnel, and acquiring vibration data of the test boreholes that are collected by the blasting vibration sensors;
• acquiring a blasting point distance for the test boreholes in the region in front of the tunnel face, and fitting a Sadovsky formula by using the vibration data and the blasting point distance of the test boreholes in the region in front of the tunnel face, thereby obtaining a first blasting vibration velocity prediction model in the region in front of the tunnel face;
• acquiring a blasting charge amount of the subsequent tunnel, substituting the vibration data of the test boreholes in the region behind the tunnel face and the blasting charge amount into the first blasting vibration velocity prediction model, and performing calculation to obtain an actual blasting point distance that stress waves are propagated from a blasting source to the test boreholes;
• and
• fitting the Sadovsky formula by using the actual blasting point distance and the vibration data of the test boreholes in the region behind the tunnel face to obtain a second blasting vibration velocity prediction model in the region behind the tunnel face, comprising:
• acquiring center coordinates of borehole openings of the test boreholes in the region behind the tunnel face;
• performing inversion according to the center coordinates of the borehole openings and drilling depths to obtain center coordinates of the borehole bottoms of the test boreholes in the region behind the tunnel face;
• acquiring coordinates of the blasting source of the tunnel face, and according to the coordinates of the blasting source, the center coordinates of the borehole bottoms and the actual blasting point distance, performing inversion by using a coordinate system inversion method to obtain a propagation path of the stress waves reaching the borehole bottoms of the test boreholes in the region behind the tunnel face;
• and
• fitting the Sadovsky formula on the basis of the propagation path to obtain the second blasting vibration velocity prediction model in the region behind the tunnel face,
• wherein the blasting vibration sensors are mounted at the borehole bottom of each test borehole, and each blasting vibration sensor comprises:
• a sensor body located at an upper part of the blasting vibration sensor;
• an accommodation chamber located at a lower part of the blasting vibration sensor, wherein a blocking layer is provided between the accommodation chamber and the sensor body, and a plurality of through holes are provided in the accommodation chamber in a peripheral direction;
• and
• a push-pull device located inside the accommodation chamber, wherein a top of the push-pull device is fixedly connected to a top surface inside the accommodation chamber, a plurality of support rods of the push-pull device extend outward along the plurality of through holes to come in contact with an inner wall of the test borehole, thereby fixing the blasting vibration sensor in the test borehole;
• wherein the push-pull device comprises:
• a push-pull rod, wherein a spring is provided inside the push-pull rod in a vertical direction, a slider is sleeved outside the push-pull rod in the peripheral direction, the slider axially slides along the push-pull rod, and a button is provided below the push-pull rod;
• an end handle, wherein a clamping port is provided on a side wall of the end handle, and the end handle is fixedly connected to the button through the clamping port;
• a rod cap, the rod cap being fixed to a top of the push-pull rod;
• and
• a pulley assembly, the pulley assembly comprising a fixed pulley, the slider and a traction rope, wherein the fixed pulley is fixed to the rod cap, the slider is sleeved outside the push-pull rod and moves axially along the push-pull rod, one end of the traction rope is connected to the fixed pulley and the slider in sequence, and another end of the traction rope passes axially through an interior of the spring and then is connected to a hook.