Principle and mathematical method for inverting stress State of a medium from the remote sensing data

It has been proved through experiments that the electromagnetic radiation energy of a substance will vary when stress acts on the substance. This moment, the electromagnetic radiation energy (observation value) received by the remote sensor is triggered not only by the substance temperature and also by the stress. Separating quantitatively these two kinds of electromagnetic radiation energy and then inversing the actual temperature state and stress state of a medium is a matter with practical significance in earthquake prediction and stability monitoring for the large-scale geotechnical engineering. In this paper the principle and the mathematical method for inversing stress by using multiband remote sensing data are discussed in detail. A calculation example is listed.     

Study of Triggering Action Between the Mani （Ms7.9） and the West Kunlun Mountains Pass （ Ms 8.1 ） Great Earthquakes and Their Dynamic Background

Based on Coulomb static stress variation, the stress trigging action of the Mani ( Ms7.9, Nov.1997) earthquake on the West Kuulun Mountains Pass (MsS.1, Nov. 2001 ) earthquake is researched. Results of different source mechanism resolutions show that a 10_3 MPa Coulomb stress due to the Mani earthquake was added to the fracture fault of the Kunlun earthquake, and this may shift the broken date to about 10 years earlier, and infer that the stress level in the crust is not low. Comparing the relationship between strong earthquake strength and frequency and earth rotation change, it is shown that the strength‘s decrease and the variation period‘ s shortening of earth rotation are important controlling factors on strong earthquake activity. This great event with Ms = 8.1 took place probably due to a gradual strengthening background of regional stress field within the Qinghai-Xizang block in the period of acceleration of change of day‘s length and stress triggering from the Mani earthquake.     

APPLICATION OF SOME MECHANICAL CONCEPTS TO STRUCTURAL GEOLOGY

This paper discusses some mechanical concepts that have been largely applied to structural geology and tectonics, and addresses the problems and misunderstandings in use of these mechanical terms. The purpose is to stimulate the interests for structural geologists in using the mechanical principles and methods correctly to solve the geodynamic problems.     

地震前地表重力场变化的一种可能解释——应力-损伤耦合效应

文中运用损伤力学研究方法 ,提出孕震过程中引起地壳破坏的应力 -损伤耦合效应。利用应变等效性假设 ,推导了地壳体的应力 -损伤耦合效应与地表重力变化之间的理论关系。根据岩石力学实验的不同加载途径 ,模拟了 1976年唐山 7 8级地震和 2 0 0 1年昆仑山口西 8 1级地震重力演化的不同特征 ,结果与实际情况符合较好 ,表明应力 -损伤耦合效应可以作为地震前地壳重力变化的一种物理解释     

地震视应力用于震后趋势快速判定的可能性

对多次强震的地震视应力进行了计算，将各次强震的地震视应力的高低与强震发生后的后续地震的强度进行联系，探索它们之间的关系，进而提出将地震视应力用于强震震后趋势预测的可能性。对多次强震的地震视应力与其后续地震强度的关系的分析结果表明，低视应力的强震的后续地震的强度一般较低，即低视应力的强震发生后，震区发生较强的后续地震的可能性较小。     

基于自平衡力的弹塑性动力反应分析方法

本文给出了一个基于自平衡力的弹塑性结构动力反应分析的新方法，详细叙述了方法的原理和过程，并对用改进的Ｔａｋｅｄａ滞变模型描述的梁单元框架结构给出了具体的分析方法。这个方法与传统的方法不同，在分析中不必修正结构的刚度矩阵，而代之以计算代表塑性铰变形引起的应力重分布的动力自平衡力，因而大大地节省了计算机时，最后通过算例对本文方法进行了验证。     

中强地震前油井动态异常机理研究

在分析油井映震特征的基础上，着重对油井动态异常的形成机理进行了研究。认为：映震灵敏井孔的空间分布主要受应力易于集中的构造条件的控制，特别是断层的又汇处、转折端和断裂带，这是与其他流体观测项目的相同之处；在本研究中，首次提出了油井动态前兆异常形成的三种力学过程，即岩土力学过程、水动力学过程和气体动力学过程以及油井特有的二种”放大”作用（变径和气体膨胀）的观点；解释了油井动态震前多为正异常的力学机制。     

线性和非线性风应力对海-气耦合波的影响

在略去Ｒｅｙｌｅｉｇｈ摩擦和Ｎｅｗｔｏｎ冷却的条件下，采用定常的线性大气模式和半地转近似的非线性海洋模式，讨论了线性和非线性风应力对海－气耦合Ｒｏｓｓｂｙ波的影响，结果表明，当耦合波处于非线性不稳定的情况下，线性和非线性风应力均可产生孤立波，不同之处在于，非线性风应力所产笺波图像具有间断特点，波能的急剧聚集有可能使波的性质发生变化。     

土的应力—应变函数及其应用

根据对压力ｐ与孔隙比 ｅ的关系研究，本文提出了极小孔隙比ｅｍｉｎ的概念，建立了应力一应变函数，探讨了主尖力－应变函数的几点应用。