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把断裂力学中的应变能释放率公式和裂纹错开位移公式运用到地震破裂中来,再用震级—能量公式logε_e=α_1M+α_2,对于走向滑动、倾向滑动和圆盘形剪切破裂找到了震源参数和地壳应力状态之间的内在联系,汇总在表2。对于走滑断层情形,关系式如下: (1) (2) (3) (4)应力降 (5)平均应力 (6)用Mo和L~2W求区域应力公式式中,M为震级,L、W为断层长度和宽度,η为地震效率,τ_0为区域剪切应力,τ_y为剪切屈服强度,μ为刚性系数,v为泊松比,为平均位错,M_0为地震矩。 利用(6)式或(1)式,在实验室测出地壳状态下屈服强度τ_y,后,可用地震观测资料算出区域剪切应力τ_0。 上述关系式和目前流行的震源参数之间的关系式有很大的差别。原因是以往只考虑了破裂的初态和终态,没有考虑破裂过程。而断裂力学恰恰是考虑了破裂过程。
Applying the formula of strain energy release rate and the misaligned displacement formula to the earthquake rupture, the magnitude-energy formula logε_e = α_1M + α_2 is used to find the source for the strike-slip, dip-slip and disc shear failure The intrinsic relationship between parameters and crustal stress conditions is summarized in Table 2. For strike-slip faults, the relationship is as follows: (1) (2) (3) (4) stress drop (5) average stress (6) Find the regional stress formula with Mo and L ~ , W is the fault length and width, η is the seismic efficiency, τ_0 is the regional shear stress, τ_y is the shear yield strength, μ is the stiffness coefficient, v is the Poisson’s ratio, is the average dislocation, and M_0 is the seismic moment. Using (6) or (1), the yield strength τ_y in the crust can be measured in the laboratory. After that, the regional shear stress τ_0 can be calculated by the seismic observation data. There is a big difference between the above relationship and the prevailing hypocenter parameters. The reason is that in the past only considered the rupture of the initial state and final state, did not consider the rupture process. The fracture mechanics precisely considers the rupture process.