Formation speed test system and test method

Abstract

The invention relates to a formation speed test system and test method. The system comprises a high-energy electric spark source, a plurality of ground detectors, one to two receiving lines, a seismograph and a triggering timing device. According to the formation speed test system of the invention, high-energy electric spark is excited in a hole, and the plurality of detectors are linearly arranged on the ground to receive seismic waves. The test system has strong excitation energy and high main frequency; the test system receives longitudinal wave first arrivals in a multi-channel manner, which realizes easiness in distinguishing; the test system can pick up first arrivals in a common-excitation point and common-receiving interactive pickup manner, so that longitudinal and transverse wavefirst arrival time can be picked up; a speed obtained through a tomographic inversion method has high precision; the formation speed test system and test method are not only suitable for soil layers,but also suitable for rock formations; and a formation speed acquired by the test system and test method is accurate and reliable and is similar to a result obtained by an in-situ wave speed test.

Description

technical field [0001] The invention relates to the technical field of engineering survey, in particular to a formation velocity testing system and testing method. Background technique [0002] In the current engineering survey process, it is necessary to obtain the following series of rock and soil mechanical parameters based on the elastic characteristics of rock and soil, and by measuring the propagation velocity of longitudinal waves and shear waves in different rock layers. Based on this, the engineering properties of rock and soil layers can be judged, and a reliable scientific basis can be provided for seismic design and safety assessment. The current status of the more common testing methods are as follows: [0003] 1.Traditional tomography test [0004] The layer inspection method is a more commonly used wave velocity test method, which can test the wave velocity of soil layers and rocks. The ground excitation is used to generate the elastic wave, and the elastic...

AI Technical Summary

Problems solved by technology

[0008] Coring test is required, the velocity of complete rock is accurate, the velocity of damaged rock is inaccurate, and the velocity of soil cannot be measured

[0009] In summary, the first method is suitable for soil layers and rocks, but it is relatively easy to test the shear wave velocity, it is difficult to obtain high-quality longitudinal wave test data, and the accuracy of the test results is difficult to guarantee, while the second and third methods The method is not suitable for the soil layer, so there is an urgent need for a simple and quick practical method to solve this problem

Images