蒙脱石的脱水作用对断层摩擦本构行为的影响

利用高温双轴摩擦装置，研究了含蒙脱石的断层带在不同温度下摩擦滑动的速度依赖性，以期了解脱水作用对摩擦行为的影响。结果表明，断层带摩擦强度随温度而升高，而速度依赖性较为复杂，以１．４ｕ／ｓ为界，室温和１００℃时，低滑动速率下表现为微弱的速度弱化，高滑动速率下则表现为速度强化；２００℃时均为速度强化；３００℃时高滑动速率下仍为速度强化，但低滑动速率下转变为速度弱化；４００℃以上，均为明显的速度弱化。摩擦行为的变化与脱水过程及相应的断层物质变形方式的变化密切相关     

Role of in situ cosmogenic nuclides 10be and 26al in the study of diverse geomorphic processes

The central premises of applications of the in situ cosmogenic dating method for studying specific problems in geomorphology are outlined for simple and complex exposure settings. In the light of these general models, we discuss the information that can be derived about geomorphic processes, utilizing concentrations of in situ produced cosmogenic radionuclides ¹⁰Be (half-life=1·5 ma) and ²⁶A1 (half-life=0·7 ma) in a variety of geomorphic contexts: glacial polish and tills; meteorite impact craters; alluvial fans; paleo-beach ridges; marine terraces; sand dunes; and bedrock slopes. We also compare ¹⁰Be-²⁶Al data with results obtained by other dating methods. We conclude that the technique of measuring in situ cosmic ray produced nuclides holds promise for quantitative studies of processes and time-scales in a wide range of geomorphological problems.     

岩石软化温度及其在地球深部岩石力学性质研究中的意义

从高温高压岩石力学实验的角度阐述了岩石软化的现象,提出岩石软化温度的概念和定义以及测量方法.根据对大量经过高温变形试件的显微结构观察,从岩石中各矿物组分对不同温度下的变形反应和机制出发,认为岩石软化现象的本质是岩石中的各矿物组分在高温下逐步由脆性变形向韧性变形和塑性变形转化过程中在岩石力学性质上的综合反映.提出岩石中矿物变形序次及不同组分矿物在岩石中的结构位置和含量是决定岩石软化温度的主要因素.由此进一步讨论了岩石中矿物的变形序次对地壳内岩石脆-韧性变形转化条件的影响及其在地球深部岩石力学性质和地震孕育理论研究中的重要意义.     

上海青浦福泉山遗址出土石器的岩石类型与特征

青浦县福泉山古文化遗址,经本市考古工作者的多年发掘,从崧泽文化与良渚文化墓葬群中出土了一批石制生产工具和礼器,其中包括斧、钺、(石奔)、凿,矢、刀、铲、镰刀、三角形大刀、锥形器及砺石(磨刀石)等共计10余种。这批工具主要由变质岩类与岩浆岩类岩石磨制而成。选用石料质地坚硬,加工精美,说明5000年前的上海先民,已具有颇高的智慧与创造力。     

Developments in a non-destructive method of determining rock strength

Material strength is an important variable for any study of the relationships between rock mass geomechanical characteristics and landform development. Standard field and laboratory tests for measuring strength present a variety of problems to the geomorphologist. Recent studies (Allison, 1988) have described a laboratory based non-destructive method for indirectly determining material strength, by measuring Dynamic Young's Modulus. Data presented here suggest that the same apparatus can be used as a field technique. Tests have been conducted on the Devonian limestone of the Napier Range, Western Australia. Laboratory results obtained using the non-destructive ultrasonic apparatus have a high correlation with triaxial Hoek Cell tests. Results from on-site tests have much greater accuracy than data collected using the Schmidt hammer, which is currently the most widely used geomorphological field technique for determining rock strength.     

花岗岩压缩带电的实验研究

在单轴压力下用测量微电流方法对花岗岩标本表面的电荷性质进行了实验研究,同时对产生这种表面电荷的可能原因进行了分析.     

Q P and Q S in Beijing and Jianchuan, Yunnan areas

Events from the December 1982 Huairou County, Beijing, and the July 1982 Jianchuan, Yunnan earthquake series were recorded at one station in Beijing City and at four stations in Eryuan area, Yunnan, respectively. Dividing the spectra (for P and S waves) from the smaller events in the series by spectra (for corresponding P and S waves) from the larger events in cach region, we have determined the high frequency source spectral decay rate to be ω⁻¹in both cases. Through trial and error method, we are able to determine the appropriate constantQ _P andQ _S that corrects the individual spectra to the proper high frequency decay rate. It is found that aQ _P of 800 and aQ _S of 550 can adequately compensate for the attenuation of the waves in Beijing area. For Jianchuan, Yunnan area the corresponding values are 900 and 400. This subject is supported by Chinese Joint Seismological Science Foundation.     

岩石破裂中的电子发射

利用G-M计数器和塑料闪烁体探测器在花岗岩单轴压缩破裂实验中首次记录到电子发射,电子能量分别为0.05McV和0.35MeV量级。根据这一结果提出了岩石破裂中出现可见光及其它电磁辐射的理论解释。     

A non-destructive method of determining rock strength

Rock material strength is an important component of many geomorphological studies. Current methods for determining this parameter result in sample destruction, preventing further analysis. A new non-destructive technique is described for indirectly determining material strength, by measuring Dynamic Young's Modulus. Tests have been conducted on Jurassic Portland Limestone and Upper Cretaceous Chalk to assess the apparatus. Young's Modulus is becoming an increasingly important rock material property.     

Rock mass characterization using photoanalysis

Summary Rock formations are distinguished from each other by measuring first the properties of the intact rock, and second those of the jointing. Whereas simple methods are available for measuring intact rock properties, those available for measuring jointing remain slow, expensive, and sometimes dangerous. Digitized photographs (photoanalysis) may provide a solution. In this paper, the new techniques of photoanalysis are reviewed together with applications, promising areas for research, and also some obstacles that remain to be overcome. Aspects of the rock mass that lend themselves to photoanalytical measurement include those of individual joints, such as persistence, orientation and roughness, and those relating to the mass as a whole, such as block size and the spacing or intensity of jointing. Photoanalysis can also be applied to measurement of blasting. It allows characterization of the rock about to be blasted, helping the engineer to predict fragmentation and to design an appropriate blasting pattern. Afterwards, the same methods can be used to measure fragmentation, overbreak and backbreak, for quality control and for diagnosis of problems.Presented at the 28th US ROck Mechanics Symposium, Tucson, Arizon, 29 June–1 July 1987.