CN102141545A - Method for testing rock mass mechanics parameters based on explosion seismic wave space-time attenuation law - Google Patents

Abstract

The invention relates to a technology for testing rock mass mechanics parameters, in particular to a method for testing rock mass mechanics parameters based on an explosion seismic wave space-time attenuation law. The method comprises the steps of data testing and test data processing; and geometric parameters and mechanics parameters of rock mass can be obtained by corresponding testing and calculating. The parameters mainly comprise the viscosity coefficient of the rock mass, the equivalent elastic modulus of the rock mass, an azimuth angle of a structural plane, the rigidity of the structural plane, the thickness of the structural plane, and the elastic modulus of the structure plane; and the relevant parameters of the rock mass are given for analysis of slope stability.

Description

Rock mass mechanics parameter test method based on attenuation of seismic waves space-time attenuation law

Technical field

The present invention relates to rock mass mechanics parameter testing technology, is a kind of rock mass mechanics parameter test method based on attenuation of seismic waves space-time attenuation law.

Background technology

The engineering construction development of current China rapidly, increasing traffic engineering, Hydraulic and Hydro-Power Engineering, energy project, mining mineral resource engineering and defence engineering etc. are built in the unfavorable geological condition area, in the medium-term and long-term development plan of China, " 13 " will put 49 large hydropower stations before into operation, the year two thousand twenty china railway operation mileage will increase to 100,000 kilometers, will build the freeway net of 8.5 ten thousand kilometers of mileages before the year two thousand thirty; In the newly-increased 4,000,000,000,000 economic stimulus packages investment of country, have 38% to put into infrastructure constructions such as railway and highway, the large-scale engineering construction that these are about to carry out will run into complicated rock mass to some extent, and its engineering design, construction, estimation of stability and geologic body reinforcing etc. all depend on the mechanics parameter of accurate acquisition rock mass.

The rock mass mechanics parameter is difficult point but is the key issue that must solve in the estimation of stability of joint rock mass engineering project.The approach that obtains joint rock mass mechanics parameter at present mainly contains methods such as experimental formula, back analysis, shop experiment, site test and numerical analysis.

The experimental formula method is considered to influence all multifactor of rock mass mechanics parameter, draws more definite quantification experimental formula, and the utilization experimental formula determines that the mechanics parameter of rock mass is a kind of effective method.Have diversity and complicacy owing to influence the factor of engineering rock mass quality, existing empirical method exists bigger limitation, all has the To be improved part, and its scope of application is separately arranged in other words.Its parameter estimation to the labyrinth rock mass is often too conservative, and lacks the numerical value platform and be suitable for the constitutive model and the parameter of special construction rock mass with foundation, and empirical method can not reflect well that rock mass anisotropy and tax deposit ambient stress in addition.At problems such as the non-linear and measurement data of the height of rock mass deformation are limited, the back analysis method of rock mass mechanics parameter has been proposed, this method can effectively solve the ambiguity at random that measurement data is caused by various interference, but since be difficult to monitor moderate finite deformation that moment off-load that construction causes produces and how effectively the back analysis problems such as structural information that go out rock mass also do not obtain fine solution, influenced the application of back analysis method.

The shop experiment method is meant the mechanics parameter that obtains sillar by shop experiment, design feature in conjunction with rock mass is carried out the mechanics parameter reduction, because choosing of reduction coefficient has certain subjectivity, make the mechanics parameter of rock mass certain discrepancy be arranged unavoidably, so Important Project adopt site test to determine the mechanics parameter of rock mass more with actual.Adopt field testing procedure to determine that the rock mass mechanics parameter can reflect the natural characteristic of rock mass preferably, much more reasonable than the test of laboratory sillar undoubtedly, but the restriction that in-situ test is subjected to various conditions usually such as the cycle is long, testing cost is high, test findings have bigger discreteness.Research according to Japanese scholar OdoMA, when the rock mass specimen size is long greater than 3 times of typical joint marks, its test relative error just can be accepted, if the mechanics parameter of wanting to obtain can reflect larger-size structural plane, adopting the site test of load mode almost is can not be getable.Obtain the rock mass mechanics parameter if adopt the mode of numerical evaluation, have an important problem is exactly how accurate and effective is determined the rock mass structure parameter, the particularly geometry of rock mass inner structure face and mechanics parameter, this problem also is not well solved at present, has influenced the confidence level of result of calculation.M ü ller thinks and does not rely on site test fully, for now, it is impossible describing rock mass character, have only by site test results and just may correctly judge rock mass strength and deformation properties, but traditional on-the-spot test method is difficult to carry out the rock sample test of large volume, and the dynamic testing method of rock mass can carry out the test of large volume, can finely address this problem.

Summary of the invention

The objective of the invention is to overcome existing rock mass mechanics parameter test method defective and a kind of rock mass mechanics parameter test method based on attenuation of seismic waves space-time attenuation law is provided.

Technical solution of the present invention: a kind of rock mass mechanics parameter test method based on attenuation of seismic waves space-time attenuation law, comprise the processing of data test and test data, the step of data test is as follows:

The first step: the mechanics parameter and the physical parameter of testing experiment zone sillar, the flexible modulus of parameter, Poisson ratio and the density that need test, select representational sillar at pilot region, be processed into the standard rock sample, with the mechanics parameter of rock test rig test rock, adopt the density of conventional method test sillar;

Second step: the coefficient of viscosity of test sillar, select the zone of the representative and surfacing of lithology at pilot region, arrange the three-component acceleration transducer on the face of land, sensor is bonded in the surface of pilot region with gesso, apply a shock load at pilot region, with the vibrational waveform of Acquisition Instrument record measuring point;

The 3rd step: the rock mass mechanics parameter in testing experiment zone, a boring is played in the center in test zone, and the aperture is 40～80mm, and hole depth is controlled by testing requirements, is generally 5～80m, and face of land placement sensor is with Acquisition Instrument record measuring point vibrational waveform;

Test data is treated to:

In the communication process, the peak value of space each point increases with propagation distance and decays seismic event, is the negative exponent match seismic event peak value of e and the relation of propagation distance with the truth of a matter, obtains the attenuation of seismic wave coefficient in rock mass; The amplitude of space every bit increases in time and decays, and is the amplitude of negative exponent match measuring point of e and the relation of time of vibration with the truth of a matter, obtains attenuation of seismic wave speed, and the test data treatment step is as follows:

The first step: the coefficient of viscosity of computing rock, (1) adopt Fast Fourier Transform (FFT) to carry out spectrum analysis, find out the 1st characteristic frequency of P ripple; (2) carry out bandpass filtering according to the effective bandwidth of the 1st characteristic frequency, obtain the 1st characteristic frequency characteristic of correspondence waveform; (3) obtain the rate of decay of signature waveform with the negative exponent match; (4) rock abstract be viscoelastic body, utilization wave equation and plural theory are set up the relational expression 1 of attenuation of seismic wave speed and coefficient of viscosity, the elastic modulus of the rate of decay of measuring point, the 1st characteristic frequency, sillar and Poisson ratio substitution relational expression 1, calculate the coefficient of viscosity of sillar, wherein: rate of decay and the 1st characteristic frequency are directly tried to achieve by the measuring point waveform, the elastic modulus of sillar and Poisson ratio obtain relational expression 1 by the laboratory experiment test

${\mathrm{\α}}_t=\frac{{\mathrm{\ω}}^2({\mathrm{\λ}}^{\′}+2{\mathrm{\μ}}^{\′})}{4(\mathrm{\λ}+2\mathrm{\μ})}\frac{\sqrt{1+{\left[\frac{\mathrm{\ω}({\mathrm{\λ}}^{\′}+2{\mathrm{\μ}}^{\′})}{\mathrm{\λ}+2\mathrm{\μ}}\right]}^2}+1}{1+{\left[\frac{\mathrm{\ω}({\mathrm{\λ}}^{\′}+2{\mathrm{\μ}}^{\′})}{\mathrm{\λ}+2\mathrm{\μ}}\right]}^2}$

In the relational expression 1: ω is the earthquake wave frequency, α _tBe the rate of decay of seismic amplitude, λ and μ are the elasticity Lame's constant, and λ ' and μ ' they are the viscosity Lame's constant, λ wherein, and μ, λ ' and μ ' are calculated as follows:

Relational expression 11 $\left\{\begin{array}{c}\mathrm{\λ}=\frac{\mathrm{Ev}}{(1+\mathrm{\υ})(1-2\mathrm{\υ})}\\ {\mathrm{\λ}}^{\′}=\frac{\mathrm{\η\ωv}}{(1+v)(1-2v)}\end{array}\right.$ Relational expression 12 $\left\{\begin{array}{c}\mathrm{\μ}=\frac{E}{2(1+v)}\\ {\mathrm{\μ}}^{\′}=\frac{\mathrm{\η\ω}}{2(1+v)}\end{array}\right.$

In the relational expression 11,12: E is an elastic modulus, and η is a coefficient of viscosity, and v is a Poisson ratio;

Second step: according to the position angle that the peakedness ratio Changing Pattern of polarization angle and P ripple and SV ripple calculates rock mass discontinuity, (1) carries out wave field separation according to the spatial relation of measuring point and focus, obtains P ripple and SV ripple; (2) calculate the polarization angle of each measuring point and the peakedness ratio of P ripple and SV ripple, and draw respectively the two with the variation relation figure of orifice distance, determine the structural plane inclination angle according to this figure; (3) multi-faceted test, the structural plane position angle is determined in conjunction with the test orientation in analytical structure face inclination angle;

The 3rd step: base area seismic wave attenuation law calculates the equivalent elastic modulus of rock mass, and (1) carries out wave field separation according to the spatial relation of measuring point and focus, obtains P ripple and SV ripple; (2) the P ripple that wave field separation is obtained adopts Fast Fourier Transform (FFT) to carry out spectrum analysis, finds out the 1st characteristic frequency; (3) carry out bandpass filtering according to the effective bandwidth of the 1st characteristic frequency, obtain signature waveform, determine the rate of decay of signature waveform with the method for data fitting; (4), adopt relational expression 1 to calculate equivalent elastic modulus by the coefficient of viscosity and the Poisson ratio of the rate of decay of each measuring point, the 1st characteristic frequency, rock;

The 4th step: calculate rock mass discontinuity rigidity, (1) wave field separation obtains P ripple and the SV ripple in the sillar, obtain the 1st characteristic frequency of P ripple and SV ripple by spectrum analysis, with the effective bandwidth of the 1st characteristic frequency correspondence each measuring point is carried out filtering and obtain signature waveform, obtain the rate of decay of signature waveform in the sillar; (2) carry out wave field separation and obtain P ripple and SV ripple in the rock mass, the inclination angle and the spacing of the dominance structure face of determining rock mass in conjunction with appearing, ratio ζ＞0.25 with spacing of structural planes and wavelength serves as according to the filter range of determining seismic event in the rock mass, filtering obtains the signature waveform of P ripple and SV ripple, asks the characteristic frequency and the rate of decay thereof of signature waveform; (3) set up the relational expression 2 of relative attenuation speed and rock mass discontinuity transmission coefficient by theoretical research, used this relational expression 2, calculated total transmission coefficient that seismic event passes too much structural plane by the ratio of rock mass to be measured and the rate of decay of complete sillar; (4) determine the structural plane quantity of focus in conjunction with appearing, calculate the transmission coefficient of single structure face by total transmission coefficient to each measuring point; (5) according to the mechanical characteristic of structural plane definitely seismic wave at the propagation model of structural plane, with non-packed type solid structure face abstract be spring, the packed type structural plane is abstract in certain thickness viscoelasticity thin layer is arranged, set up corresponding seismic event transmission model respectively, computation structure face rigidity, filling thickness and elastic modulus; (6) the structural plane parameter that calculates, comprise the attenuation model of the coefficient of viscosity substitution seismic event peak value of mechanics parameter, geometric parameter and rock with propagation distance, check result of calculation whether contentedly seismic wave with the attenuation coefficient of propagation distance, if do not satisfy, adjust the structural plane parameter, try to achieve the optimum solution of seismic wave rate of decay and attenuation coefficient contentedly

Relational expression 2

$\frac{{\mathrm{\α}}_{\mathrm{At}}}{{\mathrm{\α}}_{\mathrm{Bt}}}=\frac{{\mathrm{\λ}}_B^2}{{\mathrm{\λ}}_A^2}\frac{T_{A1}^{{2n}_A}}{T_{B1}^{{2n}_B}}\frac{C_A\·[{\mathrm{\ρ}}_A{\mathrm{\ω}}_A^2{P}_A+2(P_A\×A_A)\×(M_{\mathrm{AI}}{P}_A-M_{\mathrm{AR}}{A}_A)]}{C_B\·[{\mathrm{\ρ}}_B{\mathrm{\ω}}_B^2{P}_B+2(P_B\×A_B)\×(M_{\mathrm{BI}}{P}_B-M_{\mathrm{BR}}{A}_B)]}\frac{({\mathrm{\ρ}}_B{\mathrm{\ω}}_B^2{\left|P_B\right|}^2+{2M}_{\mathrm{BR}}{|P_B\×A_B|}^2)}{({\mathrm{\ρ}}_A{\mathrm{\ω}}_A^2{\left|P_A\right|}^2+{2M}_{\mathrm{AR}}{|P_A\×A_A|}^2)}$

In the formula: subscript A and B represent the parameter of rock mass A and rock mass B, α respectively _tBe the rate of decay of seismic amplitude, can directly try to achieve by waveform; λ is a wavelength, can directly be tried to achieve by velocity of wave and frequency; T is the transmission coefficient of seismic event at structural plane, is parameter to be asked; C is the vector velocity of wave, is the actual measurement parameter; ρ is a density, is the actual measurement parameter; ω is the earthquake wave frequency, can directly be tried to achieve by waveform; P is the propagation of seismic wave vector, P=ω/C, and, can directly try to achieve by velocity of wave and frequency; A is the decay vector of seismic event peak value with propagation distance, can directly be tried to achieve by the crest value match of multi-measuring point; M _IWith the real part and the imaginary part of difference complex shear modulus, M _R=μ, M _I=μ ' under the condition of determining elastic modulus and coefficient of viscosity and frequency, is calculated by relational expression 12; N is the structural plane quantity of focus to measuring point, determines the structural plane average headway by appearing and determines structural plane quantity in conjunction with focus to measuring point distance.

Beneficial effect of the present invention: (1) only needs to beat a bite vertical shaft, need not to carry out a large amount of borehole investigations, has both saved great amount of manpower and material resources and financial resources, saves a large amount of time again, has improved work efficiency widely; (2) under the condition that need not the disturbance rock mass, can test geometry and the mechanics parameter that obtains rock mass, mainly contain: the position angle of the coefficient of viscosity of sillar, the equivalent elastic modulus of rock mass, structural plane, structural plane rigidity, structural plane thickness and elastic modulus thereof; (3) seismic wave attenuation is more responsive to the structural change of rock mass than velocity of wave, adopts this method to test to obtain the mechanics parameter of non-packed type solid structure face in the rock mass; (4) adopt by the rate of decay analysis of seismic event amplitude with by the method that attenuation coefficient is checked and determine the mechanics parameter of rock mass, guaranteed the reliability of result of calculation.

Embodiment

Employing the present invention certain super-huge strip mining transformation copper mine has at home carried out underground test, for Analysis of Slope Stability provides the rock mass mechanics parameter.

Data test:

The first step: the basic mechanical parameter and the physical parameter of test sillar, select representational sillar at pilot region, be processed into the standard rock sample, elastic modulus, Poisson ratio and the density of test sillar.

Second step: the coefficient of viscosity of test sillar, select the zone of the representative and surfacing of lithology at pilot region.Arrange the three-component acceleration transducer on the face of land, the x direction of sensor is consistent with the sensor trend, and the y direction is vertical with the sensor trend, and the z direction is a vertical direction, and the parameter of sensor is: charge sensitivity 10.427～14.091pC/ms ^-2, frequency response 0.2～5kHz; Resonance frequency 15kHz.The iron ball of 3kg is from the free-falling of 1m eminence, and the bump sillar produces shock load.The INV306 vibration acquisition instrument that vibration signal is produced with Beijing Orient vibration and noise technical institute after signal condition instrument Filtering Processing is again gathered vibration signal, and is stored in the computer, and the signal condition instrument is set to low pass 3kHz, and sampling rate is 12kHz.

The 3rd step: the rock mass mechanics parameter in testing experiment zone, a boring is played in the center in test zone, and the aperture is 40mm, hole depth is 20m, downhole explosion, and dose is 40g, face of land placement sensor with Acquisition Instrument record measuring point vibrational waveform, and is stored in the computer.In this test, the layout of sensor, the parameter setting, the setting of signal condition instrument is all identical with second step with sampling rate.

The data that above-mentioned 3 pacings examination obtains have: the mechanics parameter and the physical parameter of (1) testing experiment zone sillar: carry out the sillar sampling at pilot region, the elastic modulus that the shop experiment test obtains the sillar sample is 32.4GPa, and density is 2480kg/m ³, Poisson ratio is 0.2; The vibrational waveform of measuring point when (2) test obtains seismic event and propagates in the complete sillar of pilot region; The vibrational waveform of measuring point when (3) test obtains attenuation of seismic waves and propagates in pilot region; (4) adopt this method for checking and calculate the validity of equivalent elastic modulus, also carried out wave velocity testing in the test site, it is 3460m/s at the velocity of wave of pilot region that test obtains attenuation of seismic waves, and obtaining equivalent elastic modulus by velocity of wave is 13.2Gpa.

Above-mentioned test data is carried out following steps to be handled:

The first step: the coefficient of viscosity of computing rock, (1) adopt Fast Fourier Transform (FFT) to carry out spectrum analysis, find out the 1st characteristic frequency of P ripple, and the 1st characteristic frequency of 5 measuring points is respectively 757Hz, 600Hz, 592Hz, 500Hz, 480Hz; (2) carry out bandpass filtering according to the effective bandwidth of the 1st characteristic frequency, obtain the 1st characteristic frequency characteristic of correspondence waveform, the rate of decay of obtaining signature waveform is respectively 160s ^-1, 124s ^-1, 115s ^-1, 85s ^-1, 78s ^-1(3) the elastic modulus substitution relational expression 1 of the rate of decay of measuring point, the 1st characteristic frequency and sillar, the coefficient of viscosity that calculates sillar is respectively 21.5MPas, 26.0MPas, and 24.0MPas, 24.5MPas, 26.5MPas, average coefficient of viscosity is 24.5MPas;

Second step: according to the position angle that the peakedness ratio Changing Pattern of polarization angle and P ripple and SV ripple calculates rock mass discontinuity, (1) carries out wave field separation according to the spatial relation of measuring point and focus, obtains P ripple and SV ripple; (2) polarization angle of calculating each measuring point is respectively 103 °, 88 °, 65 °, 57 °, 81 ° (3) calculate the P ripple of each measuring point and its peakedness ratio of SV ripple is respectively 0.47,1.11,1.36,0.91,0.53, (4) and draw respectively polarization angle and peakedness ratio with the variation relation figure of orifice distance, determine that according to this figure the rock mass discontinuity inclination angle is 55～70 °, mean obliquity is 63 °; (5) multi-faceted test, analytical structure face inclination angle, determine that in conjunction with the test orientation structural plane tendency is 109～121 °, the production explosion discloses the rock mass structure of pilot region out, it is 100～120 ° with tendency that the inclination angle of appearing is 50～65 °, can think thus, adopt this method can accurate and effective to obtain the structural plane orientation of rock mass;

The 3rd step: base area seismic wave attenuation law calculates the equivalent elastic modulus of rock mass, and (1) carries out wave field separation according to the spatial relation of measuring point and focus, obtains P ripple and SV ripple; (2) the P ripple that wave field separation is obtained adopts Fast Fourier Transform (FFT) to carry out spectrum analysis, and the 1st characteristic frequency of finding out 5 measuring points is respectively 130Hz, 160Hz, 120Hz, 156Hz, 85Hz; (3) carry out bandpass filtering according to the effective bandwidth of the 1st characteristic frequency, obtain signature waveform, the rate of decay that calculates the signature waveform of 5 measuring points is respectively 18.0s ^-1, 8.6s ^-1, 14.0s ^-1, 22.5s ^-1, 7.7s ^-1(4) by the coefficient of viscosity and the Poisson ratio of the rate of decay of each measuring point, the 1st characteristic frequency, rock, adopt relational expression 1 to calculate equivalent elastic modulus and be respectively 11.0GPa, 13.9GPa, 12.0GPa, 12.5GPa, 11.2GPa average equivalent elastic modulus is 12.1GPa, obtaining equivalent elastic modulus by velocity of wave is 13.2GPa, both errors are 0.08%, consider that pilot region is non-packed type solid structure face, bigger than normal by the equivalent elastic modulus that velocity of wave calculates, can think that thus this method is feasible;

The 4th step: calculate rock mass discontinuity rigidity, (1) wave field separation obtains P ripple and the SV ripple in the sillar, obtain the 1st characteristic frequency of P ripple and SV ripple by spectrum analysis, the 1st characteristic frequency and the rate of decay of obtaining the P ripple of 5 measuring points are respectively 757Hz, 600Hz, 592Hz, 500Hz, 480Hz and 160s ^-1, 124s ^-1, 115s ^-1, 85s ^-1, 78s ^-1, the 1st characteristic frequency and the rate of decay of obtaining the SV ripple of 5 measuring points are respectively 658Hz, 608Hz, 503Hz, 438Hz, 372Hz and 151s ^-1, 118s ^-1, 92s ^-1, 87s ^-1, 72s ^-1(2) wave field separation obtains P ripple and the SV ripple in the rock mass, the inclination angle and the spacing of the dominance structure face of determining rock mass in conjunction with appearing, determine the filter range of seismic event in the rock mass, filtering obtains the signature waveform of P ripple and SV ripple, and the 1st characteristic frequency and the rate of decay of obtaining the P ripple of 5 measuring points are respectively 920Hz, 910Hz, 910Hz, 920Hz, 900Hz and 59s ^-1, 61s ^-1, 75s ^-1, 54s ^-1, 26s ^-1, the 1st characteristic frequency and the rate of decay of obtaining the SV ripple of 5 measuring points are respectively 910Hz, 920Hz, 910Hz, 910Hz, 900Hz and 49s ^-1, 55s ^-1, 65s ^-1, 58s ^-1, 23s ^-1(3) ratio by rock mass to be measured and the rate of decay of complete sillar calculates total transmission coefficient that seismic event passes too much structural plane, total transmission coefficient of the P ripple of 5 measuring points is respectively 0.153,0.163,0.201,0.140,0.072, total transmission coefficient of the SV ripple of 5 measuring points is respectively 0.120,0.139,0.164,0.142,0.058; (4) determine the structural plane quantity of focus in conjunction with appearing to each measuring point, calculate the transmission coefficient of single structure face by total transmission coefficient, the P ripple that is obtained by 5 measuring points is respectively 0.731,0.739 at the transmission coefficient of single structure face, 0.669,0.720,0.828, the SV ripple that is obtained by 5 measuring points is respectively 0.702 at the transmission coefficient of single structure face, 0.720,0.637,0.722,0.816; (5) pilot region is non-packed type solid structure face, with its abstract be spring, the computation model of the structural plane transmission coefficient that utilization Pyrak-Nolte sets up, according to P ripple and the SV ripple transmission coefficient at structural plane, and seismic wave is determined the optimum solution of structural plane normal stiffness and tangential rigidity with the attenuation coefficient of propagation distance in combination, the normal stiffness of being determined by 5 measuring points is respectively 27.0GPa/m, 21.0GPa/m, 8.0GPa/m, 17.5GPa/m, 36.0GPa/m, mean rigidity is 20.3GPa/m, and the tangential rigidity of being determined by 5 measuring points is respectively 15.0GPa/m, 12.0GPa/m, 5.0GPa/m, 5.0GPa/m 15.0GPa/m, mean rigidity are 10.4GPa/m.

Strip mining transformation through decades, the mine has formed the high gradient slope of hundreds of rice, the production great explosion is very big to the stabilizing influence of high gradient slope, and has formed geologic hazard hidden danger, adopts numerical evaluation and slope deforming to monitor the stability of the methods analyst high gradient slope that combines for this reason.Adopt the input parameter of the rock mass mechanics parameter of this method of testing acquisition as numerical evaluation, result of calculation and Monitoring Data match.

Claims (1)

1. the rock mass mechanics parameter test method based on attenuation of seismic waves space-time attenuation law comprises the processing of data test and test data, and the step of data test is as follows:

The first step: the mechanics parameter and the physical parameter of testing experiment zone sillar, the flexible modulus of parameter, Poisson ratio and the density that need test, select representational sillar at pilot region, be processed into the standard rock sample, with the mechanics parameter of rock test rig test rock, adopt the density of conventional method test sillar;

Second step: the coefficient of viscosity of test sillar, select the zone of the representative and surfacing of lithology at pilot region, arrange the three-component acceleration transducer on the face of land, sensor is bonded in the surface of pilot region with gesso, apply a shock load at pilot region, with the vibrational waveform of Acquisition Instrument record measuring point;

The 3rd step: the rock mass mechanics parameter in testing experiment zone, a boring is played in the center in test zone, and the aperture is 40～80mm, and hole depth is controlled by testing requirements, is generally 5～80m, and face of land placement sensor is with Acquisition Instrument record measuring point vibrational waveform;

Test data is treated to:

In the communication process, the peak value of space each point increases with propagation distance and decays seismic event, is the negative exponent match seismic event peak value of e and the relation of propagation distance with the truth of a matter, obtains the attenuation of seismic wave coefficient in rock mass; The amplitude of space every bit increases in time and decays, and is the amplitude of negative exponent match measuring point of e and the relation of time of vibration with the truth of a matter, obtains attenuation of seismic wave speed, and the test data treatment step is as follows:

The first step: the coefficient of viscosity of computing rock, (1) adopt Fast Fourier Transform (FFT) to carry out spectrum analysis, find out the 1st characteristic frequency of P ripple; (2) carry out bandpass filtering according to the effective bandwidth of the 1st characteristic frequency, obtain the 1st characteristic frequency characteristic of correspondence waveform; (3) obtain the rate of decay of signature waveform with the negative exponent match; (4) rock abstract be viscoelastic body, utilization wave equation and plural theory are set up the relational expression 1 of attenuation of seismic wave speed and coefficient of viscosity, the elastic modulus of the rate of decay of measuring point, the 1st characteristic frequency, sillar and Poisson ratio substitution relational expression 1, calculate the coefficient of viscosity of sillar, wherein: rate of decay and the 1st characteristic frequency are directly tried to achieve by the measuring point waveform, the elastic modulus of sillar and Poisson ratio obtain relational expression 1 by the laboratory experiment test

${\mathrm{\α}}_t=\frac{{\mathrm{\ω}}^2({\mathrm{\λ}}^{\′}+2{\mathrm{\μ}}^{\′})}{4(\mathrm{\λ}+2\mathrm{\μ})}\frac{\sqrt{1+{\left[\frac{\mathrm{\ω}({\mathrm{\λ}}^{\′}+2{\mathrm{\μ}}^{\′})}{\mathrm{\λ}+2\mathrm{\μ}}\right]}^2}+1}{1+{\left[\frac{\mathrm{\ω}({\mathrm{\λ}}^{\′}+2{\mathrm{\μ}}^{\′})}{\mathrm{\λ}+2\mathrm{\μ}}\right]}^2}$

In the relational expression 1: ω is the earthquake wave frequency, α _tBe the rate of decay of seismic amplitude, λ and μ are the elasticity Lame's constant, and λ ' and μ ' they are the viscosity Lame's constant, λ wherein, and μ, λ ' and μ ' are calculated as follows:

Relational expression 11 $\left\{\begin{array}{c}\mathrm{\λ}=\frac{\mathrm{Ev}}{(1+\mathrm{\υ})(1-2\mathrm{\υ})}\\ {\mathrm{\λ}}^{\′}=\frac{\mathrm{\η\ωv}}{(1+v)(1-2v)}\end{array}\right.$ Relational expression 12 $\left\{\begin{array}{c}\mathrm{\μ}=\frac{E}{2(1+v)}\\ {\mathrm{\μ}}^{\′}=\frac{\mathrm{\η\ω}}{2(1+v)}\end{array}\right.$

In the relational expression 11,12: E is an elastic modulus, and η is a coefficient of viscosity, and v is a Poisson ratio;

Second step: according to the position angle that the peakedness ratio Changing Pattern of polarization angle and P ripple and SV ripple calculates rock mass discontinuity, (1) carries out wave field separation according to the spatial relation of measuring point and focus, obtains P ripple and SV ripple; (2) calculate the polarization angle of each measuring point and the peakedness ratio of P ripple and SV ripple, and draw respectively the two with the variation relation figure of orifice distance, determine the structural plane inclination angle according to this figure; (3) multi-faceted test, the structural plane position angle is determined in conjunction with the test orientation in analytical structure face inclination angle;

The 3rd step: base area seismic wave attenuation law calculates the equivalent elastic modulus of rock mass, and (1) carries out wave field separation according to the spatial relation of measuring point and focus, obtains P ripple and SV ripple; (2) the P ripple that wave field separation is obtained adopts Fast Fourier Transform (FFT) to carry out spectrum analysis, finds out the 1st characteristic frequency; (3) carry out bandpass filtering according to the effective bandwidth of the 1st characteristic frequency, obtain signature waveform, determine the rate of decay of signature waveform with the method for data fitting; (4), adopt relational expression 1 to calculate equivalent elastic modulus by the coefficient of viscosity and the Poisson ratio of the rate of decay of each measuring point, the 1st characteristic frequency, rock;

The 4th step: calculate rock mass discontinuity rigidity, (1) wave field separation obtains P ripple and the SV ripple in the sillar, obtain the 1st characteristic frequency of P ripple and SV ripple by spectrum analysis, with the effective bandwidth of the 1st characteristic frequency correspondence each measuring point is carried out filtering and obtain signature waveform, obtain the rate of decay of signature waveform in the sillar; (2) carry out wave field separation and obtain P ripple and SV ripple in the rock mass, the inclination angle and the spacing of the dominance structure face of determining rock mass in conjunction with appearing, ratio ζ＞0.25 with spacing of structural planes and wavelength serves as according to the filter range of determining seismic event in the rock mass, filtering obtains the signature waveform of P ripple and SV ripple, asks the characteristic frequency and the rate of decay thereof of signature waveform; (3) set up the relational expression 2 of relative attenuation speed and rock mass discontinuity transmission coefficient by theoretical research, used this relational expression 2, calculated total transmission coefficient that seismic event passes too much structural plane by the ratio of rock mass to be measured and the rate of decay of complete sillar; (4) determine the structural plane quantity of focus in conjunction with appearing, calculate the transmission coefficient of single structure face by total transmission coefficient to each measuring point; (5) according to the mechanical characteristic of structural plane definitely seismic wave at the propagation model of structural plane, with non-packed type solid structure face abstract be spring, the packed type structural plane is abstract in certain thickness viscoelasticity thin layer is arranged, set up corresponding seismic event transmission model respectively, computation structure face rigidity, filling thickness and elastic modulus; (6) the structural plane parameter that calculates, comprise the attenuation model of the coefficient of viscosity substitution seismic event peak value of mechanics parameter, geometric parameter and rock with propagation distance, check result of calculation whether contentedly seismic wave with the attenuation coefficient of propagation distance, if do not satisfy, adjust the structural plane parameter, try to achieve the optimum solution of seismic wave rate of decay and attenuation coefficient contentedly

Relational expression 2

$\frac{{\mathrm{\α}}_{\mathrm{At}}}{{\mathrm{\α}}_{\mathrm{Bt}}}=\frac{{\mathrm{\λ}}_B^2}{{\mathrm{\λ}}_A^2}\frac{T_{A1}^{{2n}_A}}{T_{B1}^{{2n}_B}}\frac{C_A\·[{\mathrm{\ρ}}_A{\mathrm{\ω}}_A^2{P}_A+2(P_A\×A_A)\×(M_{\mathrm{AI}}{P}_A-M_{\mathrm{AR}}{A}_A)]}{C_B\·[{\mathrm{\ρ}}_B{\mathrm{\ω}}_B^2{P}_B+2(P_B\×A_B)\×(M_{\mathrm{BI}}{P}_B-M_{\mathrm{BR}}{A}_B)]}\frac{({\mathrm{\ρ}}_B{\mathrm{\ω}}_B^2{\left|P_B\right|}^2+{2M}_{\mathrm{BR}}{|P_B\×A_B|}^2)}{({\mathrm{\ρ}}_A{\mathrm{\ω}}_A^2{\left|P_A\right|}^2+{2M}_{\mathrm{AR}}{|P_A\×A_A|}^2)}$

In the formula: subscript A and B represent the parameter of rock mass A and rock mass B, α respectively _tBe the rate of decay of seismic amplitude, can directly try to achieve by waveform; λ is a wavelength, can directly be tried to achieve by velocity of wave and frequency; T is the transmission coefficient of seismic event at structural plane, is parameter to be asked; C is the vector velocity of wave, is the actual measurement parameter; ρ is a density, is the actual measurement parameter; ω is the earthquake wave frequency, can directly be tried to achieve by waveform; P is the propagation of seismic wave vector, P=ω/C, and, can directly try to achieve by velocity of wave and frequency; A is the decay vector of seismic event peak value with propagation distance, can directly be tried to achieve by the crest value match of multi-measuring point; M _IWith the real part and the imaginary part of difference complex shear modulus, M _R=μ, M _I=μ ' under the condition of determining elastic modulus and coefficient of viscosity and frequency, is calculated by relational expression 12; N is the structural plane quantity of focus to measuring point, determines the structural plane average headway by appearing and determines structural plane quantity in conjunction with focus to measuring point distance.