地震条件下损伤–愈合模型的初步研究

脆性介质的损伤与破坏是力学中极为复杂、极具挑战性的难题之一，而地震是一类典型脆性介质的突发破 裂或失稳。在地震等灾变发生前都会出现一定的前兆现象，地震之后地壳介质又会缓慢愈合，地壳介质的损伤愈 合过程对地震预测具有重要的研究意义。首先介绍V. Lyakhovsky 等提出的损伤流变模型，且结合岩石破坏声发射 实验数据分析该模型的特点；进一步基于损伤力学，从Helmholtz 自由能出发，并考虑地质材料的可愈合效应， 建立一维损伤–愈合模型，采用数值计算的方法得到地质材料的损伤–愈合模式。用常数加载率的线性载荷叠加 一个正弦扰动来模拟固体潮引力，模拟计算该加载条件下材料的损伤–愈合过程；同时也考察了整个损伤愈合演 化过程中加卸载响应比值的变化情况，发现在灾变发生之前加卸载响应比值会出现明显异常、回落的现象。再次 验证了加卸载响应比作为一种重要的前兆现象，能够定量地刻画介质的损伤演化过程，这也为加卸载响应比方法 提供了更为坚实的物理基础

A Statistical Investigation of the Earthquake Predictions Using LURR

In terms of the spatial scanning of LURR (Load-Unload Response Ratio), we have been predicting the seismic tendency within the next year for the mainland of China from 1995 to 2003. In order to make the quantitative retrospective assessment of LURR metho

LURR's Twenty Years and Its Perspective

Seismogenic process is a nonlinear and irreversible one, so that the response to loading of a seismogenic zone is different from the unloading one. This difference reflects quantitatively the process of an earthquake preparation. A physics-based new parameter-Load/Unload Response Ratio (LURR) was proposed to measure quantitatively the proximity to a strong earthquake and then used to be an earthquake predictor. In the present paper, a brief history of LURR is recalled; inspection of real earthquake cases, numerical simulations and laboratory studies of LURR, prediction efforts in terms of LURR, probability problem of LURR and its prospect are also expatiated

New progress in LURR-integrating with the dimensional method

The evolution laws of LURR (Loading-Unloading Response Ratio) before strong earthquakes, especially the peak point of LURR, are described in this paper. The results of four methods (experimental, numerical simulation, seismic data analysis and with damage mechanics analysis) lead to a consistent conclusion-the evolution laws of LURR before strong earthquakes are that, at the early stage of the seismic cycle, LURR will fluctuate around 1 and in the late stage, it rises swiftly and to its peak point. At some time after this peak point, a catastrophic event or events occur. These do not occur at the peak point, but lag behind. The lag time which is denoted by T (2) depends on the magnitude M of the upcoming earthquake among other factors. In order to consider the influence of geophysical parameters in a specific region such as E (a) and J ((t)), where is the shear strain rate of tectonic loading in situ, E (a) is the sum of radiated energy of all earthquake occurring in a specific region measured during a long time duration (110 years in this paper) divided by the area of the region and the time duration, and J ((t)) is a parameter denoting the LURR anomaly area weighted with Y (the value of LURR) and represents the expanse and degree of the seismogenic zone. The dimensional analysis method has been used to reveal the relation between M, T (2) and other parameters in situ for more reliable earthquake prediction

地震预报的新途径——加卸载响应比理论

从力学角度看,地震的孕育过程实质上是孕震区介质的损伤演化过程,这个过程主要是一个力学过程.但解决与地震预测有关的力学问题与工程中的力学问题有许多不同之处.通常力学问题的解决需要知道其本构关系、边界条件、初始条件以及某些力学量的变化历史(如流变).但是在地震孕育过程中它们却是未知的或者不完全知道的.人们知道的只是地壳中某些物理量的变化.由此提出了加卸载响应比作为一种地震预测的新途径,并简述了加卸载响应比的基本概念、实际应用及一些最新结果

地震预测与地震控制

从力学角度看,地震的孕育过程实质上是孕震区介质的损伤演化过程.但解决与地震有关力学问题与工程中的力学问题有许多不同之处.基于此提出了加卸载响应比作为一种地震预测的新途径.本文简述了加卸载响应比的基本概念、实际应用及几个最新的结果.进而讨论了地震控制问题.地震控制的实质是地壳内应变能释放方式的控制,探讨了当今科技水平条件下可能用于控制地震的几种方法.从我们进行的文献调研及预研究看,地震控制问题不是高不可攀,无从下手的

尼泊尔Ms8.1大地震的预测和未来趋势研究

编者按：中国科学院力学研究所非线性力学国家重点实验室尹祥础，主要研究领域为地震力学和地震预报理论。承蒙盛意，将他近日的报告提供本刊发表。 作者简介：尹祥础,&nbsp;&nbsp;1958&nbsp;年毕业于清华大学第一届工程力学研究班, 1984&nbsp;年在美国圣路易大学作访问学者,&nbsp;多次赴昆士兰大学等参加合作研究.&nbsp;中国地震局地震预测研究所研究员,&nbsp;中国科学院力学研究所非线性力学国家重点实验室特聘研究员,&nbsp;中国地震局地球物理研究所博士生导师,&nbsp;中国科学院研究生院兼职教授,《地震学报》&nbsp;,《中国地震》&nbsp;,&nbsp;《地震》,&nbsp;及《超级计算通讯》编委, ACES (APEC Cooperation Earthquake Simulation) ISB理事,&nbsp;历届&nbsp;ACES workshop&nbsp;主席或组委会成员,&nbsp;中国地震预测咨询委员会委员.&nbsp;享受国务院政府特殊津贴,&nbsp;两次主持国家自然科学基金委员会重点项目(脆性介质损伤累积统计和破坏预测非线性演化理论和非均匀脆性介质破坏的共性特征,&nbsp;前兆与地震预测).&nbsp;已发表学术论文一百多篇,&nbsp;专著&nbsp;2&nbsp;部.&nbsp;主要研究领域:&nbsp;地震力学,&nbsp;地震预报理论. 全新的地震预测理论-加卸载响应比（LURR）理论的创建者。该理论开辟了一条预测脆性介质中灾变（地震、水库地震、矿震、岩爆、滑坡、火山喷发等自然灾害及岩石，混凝土工程的破坏）新途径， 也可用于工程结构的健康检测。他关于该理论的研究论文已发表在国内外许多重要学术期刊上（如苏联的自然杂志--ПРИРОДА,欧洲的Pure and Applied Geophysics，美国地球物理学会AGU Monogroph，&nbsp;中国科学等）。通过对几百个中外震例的检验,证实了LURR理论的正确性，符合率高达80%。用该理论已多次成功地预报了中外地震，如美国洛杉矶地震、日本关东6.6级地震、云南丽江7级地震,和2015-4-25的尼泊尔Ms8.1级大地震等（中期预测）。2004-2007年发生在中国大陆资料达标地区的ML&ge;5地震中，90%个落入用LURR在前一年年底预测的区域内。<br /

A plate model for the damage of a crustal block induced by earthquake and the new definition for the load/unload response ratio

地震孕育的实质是孕震区介质的损伤程度不断增加,最后导致突然失稳(破坏)。研究地块的损伤演化是研究地震孕育过程的科学方法。加卸载响应比(LURR)的提出正是基于这一基本思路,把地壳块体看作平板,断层看作平板中的裂纹,建立了地壳块体的平板模型。该模型可以用来研究地震形成的断层导致的地块损伤,损伤程度用刚度的减少来刻画。研究了地块在地震影响下弹性性质的变化及损伤,并把它们作为加载与卸载响应量,进一步得到新的LURR解析式,赋予LURR以新的、更为确切的物理意义

Load-unload response ratio—An interplay between earthquake prediction and mechanics

地震预测是世界性科学难题，地震现象虽然复杂其物理实质倒是明确：地震就是地壳块体的快速剪切脆断，相应地，地震的孕育过程就是震源区介质的损伤、演化，并最终导致破坏的过程，这一过程主要是力学过程，抓住这一点就抓住了问题的物理本质，但是，在研究地震预测时遇到的力学问题和通常的（工程）力学问题有所不同，根据地震问题的特点，紧扣地震孕育过程的物理本质，提出了加卸载响应比这一地震预测新思路. 文中介绍了加卸载响应比理论的基本科学问题，包括如何对地壳加载/卸载，如何选择适当的地球物理参数作为响应量，以及怎样定义加卸载响应比，用实验研究、数值模拟和理论分析3种基础研究手段，揭示了地震孕育过程中加卸载响应比共同的演化规律：孕震初期加卸载响应比在1附近涨落，之后上升至峰值点，地震不在峰值点发生，而是在下降过程中发生，从峰值点到地震发生这段滞后时间称为T_2，T_2和震级有关，为了预测地震，必须在全国范围内作加卸载响应比的时空扫描，在时空扫描基础上，结合量纲分析,更多地考虑当地的地球物理条件，拟定了全面预测未来地震的时、空、强的思路，回顾了用这种思路进行地震预测实践的历程

A Dimensional Analysis Method for Improved Load-Unload Response Ratio

The load-unload response ratio (LURR) method is proposed to measure the damage extent of source media and the criticality of earthquake. Before the occurrence of a large earthquake, anomalous increase in the time series of LURR within the certain temporal and spatial windows has often been observed. In this paper, a dimensional analysis technique is devised to evaluate quantitatively the magnitude and time of the ensuing large earthquake within the anomalous areas derived from the LURR method. Based on the pi-theorem, two dimensionless quantities associated with the earthquake time and magnitude are derived from five parameters (i.e. the seismic energy (E (S)), the average seismic energy (E (W)), the maximum value of LURR's seismogenic integral (I (PP)), the thickness of seismogenic zone (h), the time interval from I (PP) to earthquake (T (2)), and the shear strain rate ()). The statistical relationships between the earthquakes and the two dimensionless quantities are derived by testing the seismic data of the 50 events of M4.5 similar to 8.1 occurred in China since 1976. In earthquake prediction, the LURR method is used to detect the areas with anomalous high LURR values, and then our dimensional analysis technique is applied to assess the optimal critical region, magnitude, and time of the ensuing event, when its seismogenic integral is peaked (I (PP)). As study examples, we applied this approach to study four large events, namely the 2012 M (S)5.3 Hami, 2015 M (S)5.8 Alashan, 2015 M (S)8.1 Nepal earthquakes, and the 2013 Songyuan earthquake swam. Results show that the predicted location, time, and magnitude correlate well with the actual events. This provides evidence that the dimensional analysis technique may be a useful tool to augment current predictive power of the traditional LURR approach