Method for obtaining microearthquake wave velocity based on space geometry relationship

Abstract

The invention relates to a method for obtaining a microearthquake wave velocity based on a space geometry relationship. The method comprises the following steps: constructing an inequation of microearthquake equivalent wave velocity V according to the space geometry relationship of an earthquake focus point and a base station, constructing a regularly changing time difference fitness function shaped like a quadratic function with an upward opening, proposing a monotonous unidirectional searching algorithm, and resolving an optimum wave velocity. The method perfectly solves the problem that a velocity model in microearthquake positioning is inaccurate or non-unique, and does not need any prior engineering experience; the microearthquake wave velocity can be quickly and precisely solved according to the observation data of sensors for microearthquake arrival time, so that the positional accuracy of a microearthquake positioning algorithm in a later period is guaranteed, the rate of convergence and the stability of the algorithm are improved, and the method has an extremely high practical engineering application value.

Description

technical field [0001] The invention relates to microseismic monitoring, in particular to a method for obtaining microseismic wave velocity based on spatial geometric relationship. Background technique [0002] Microseismic monitoring is one of the main monitoring technologies for mine dynamic disasters. A microseismic event is determined through the location of the source and its occurrence time, and the energy released is calculated, and then the strength and frequency of the microseismic activity are counted, and the potential distribution of the microseismic event is judged based on the location of the microseismic event. The law of mine disaster activities. In recent years, this technology has been widely used in the monitoring, monitoring and evaluation of rock mass structure stability in underground projects such as mines, coal mines, tunnels, geothermal projects, and nuclear projects, and open-pit projects such as slopes, roadbeds, and dams. [0003] It is one of th...

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Problems solved by technology

However, in practical engineering applications, the former method is the most widely used, especially the Geiger positioning method, which is the most commonly used. However, the inaccurate velocity model is the biggest shortcoming of this type of method. Although the predecessors have done a lot of research on the velocity model, it is still The biggest factor affecting the stability and positioning accuracy of the positioning algorithm

The latter better solves the problem of inaccurate velocity models, but requires the project to measure the wave velocity in advance, adding additional workload and professional engineering experience; or using the fitting form of the microseismic positioning method proposed by Dong Longjun and other scholars without velocity measurement In microseismic positioning, some or all of the quake-onset time, microseismic coordinates, and wave velocity are regarded as unknown quantities, and the arrival time difference is used as the objective function for fitting. These are nonlinear multi-extreme value problems, and only some intelligence can be used. Optimize the search algorithm to solve

For example, scholar Chen Bingrui once used the particle swarm search algorithm to solve the problem. However, due to the blindness of each parameter in the solution process, in the absence of a large amount of seismic source data constraints, there will be problems in the solution process in order to meet the minimum objective function of the equation. Serious discrepancies, and the results of the search algorithm itself are random, and sometimes even need to be re-run several times, and the efficiency is not high

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