Field estimate of paleoseismic slip on a normal fault using the Schmidt hammer and terrestrial LiDAR: Methods and application to the Hebgen fault (Montana,USA)          下载免费PDF全文

Alexander Tye  Timothy Stahl 《地球表面变化过程与地形》2018,43(11):2397-2408

The weathering characteristics of bedrock fault scarps provide relative age constraints that can be used to determine fault displacements. Here, we report Schmidt hammer rebound values (R‐values) for a limestone fault scarp that was last exposed in the 1959 Mw 7.3 Hebgen Lake, Montana earthquake. Results show that some R‐value indices, related to the difference between minimum and maximum R‐values in repeated impacts at a point, increase upward along the scarp, which we propose is due to progressive exposure of the scarp in earthquakes. An objective method is developed for fitting slip histories to the Schmidt hammer data and produces the best model fit (using the Bayesian Information Criterion) of three earthquakes with single event displacements of ≥ 1.20 m, 3.75 m, and c. 4.80 m. The same fitting method is also applied to new terrestrial LiDAR data of the scarp, though the LiDAR results may be more influenced by macro‐scale structure of the outcrop than by differential weathering. We suggest the use of this fitting procedure to define single event displacements on other bedrock fault scarps using other dating techniques. Our preliminary findings demonstrate that the Schmidt hammer, combined with other methods, may provide useful constraints on single event displacements on exposed bedrock fault scarps. Copyright © 2018 John Wiley & Sons, Ltd.  相似文献   

新型偏心跟管钻具的设计与有限元分析          下载免费PDF全文

罗宏保  宋军  赵建勤  黄晓铭 《探矿工程》2009,36(12):33-36

介绍了新型偏心跟管钻具的结构组成以及设计思路。针对跟管钻具工作环境与受力作用复杂的情况,通过对跟管钻具进行建模,设定各种载荷条件,运用有限元分析软件ANSYS11．0对跟管钻具的工况进行模拟。根据模拟分析结果能够对钻具的设计进行改进,并为新型跟管钻具设计结构的合理性和可靠性提供理论依据。  相似文献   

横波激发新技术   总被引：5，自引：0，他引：5  

张树林  朱介寿 《地球科学进展》1991,6(1):49-53

横波地震是深入认识沉积岩性、岩相的具有发展前途的崭新方法和手段。根据国外资料,对横波激发新技术中的三孔法、水平重锤法、SHOVER法与横波振动器作了介绍与比较。  相似文献   

Enhanced bedrock weathering in association with late-lying snowpatches: Evidence from Livingston Island,Antarctica     

Kevin Hall 《地球表面变化过程与地形》1993,18(2):121-129

An indication of the extent of weathering on different aspects of rock outcrops on Livingston Island, Antarctica, was obtained by means of a Schmidt hammer, a cone indenter and measurement of weathering rind thickness. Results show that weathering, particularly chemical weathering, is enhanced on the lee side of outcrops where snow accumulates as a result of prolonged wetting by the melting snow. Rock moisture and temperature data indicate that the south-facing, snow-accumulation side of obstacles have high rock moisture levels and maintain relatively high temperatures. Whilst chemical weathering is greater on the leeward side of outcrops, mechanical processes are greater on the windward side. The presence of late-lying snow thus appears to exert a strong influence on weathering.  相似文献   

用集束潜孔锤做硬岩连续墙开槽机          下载免费PDF全文

刘广志 《探矿工程》1994,(4):6-8

介绍了英格素兰公司的集束式潜孔锤的特点及性能，用集束潜孔锤施工３种不同结构连续墙的程序，着重介绍了钢板连续墙施工工序。  相似文献   

Comments on Allison's (1990) developments in a non-destructive method of determining rock strength     

Ian A. Campbell 《地球表面变化过程与地形》1991,16(5):471-472

In Developments in a non-destructive method of determining rock strength, Allison (1990) compares data collected using an ultrasonic apparatus with data obtained from Schmidt hammer tests. He concludes that the Schmidt hammer data shows a wide degree of scatter and that its accuracy as field technique is questionable. No discussion is made of how the Schmidt hammer was used or of the total number of readings taken and the range of values. The graphs presented comparing data derived from some samples using ultrasonic equipment do not appear markedly at variance from the Schmidt hammer-derived data but true comparison is not possible because the graphs use different measurement criteria. No information is given on comparative time and financial costs, which must be significantly different for the two techniques.  相似文献   

Measurement and calibration of weathering using the schmidt hammer,on wave washed moraines on the upper norrland coast,Sweden     

R. Sjberg  N. Broadbent 《地球表面变化过程与地形》1991,16(1):57-64

The Schmidt hammer has for some years been used to measure the hardness of different rock surfaces and to date relatively boulders in moraine deposits. In this paper applications on isostatically raised boulder-beaches and rocky shores are described. The research area is the northern Swedish Bothnian coast where present isostatic uplift is between 0.8-1.0 cm year^?1. Elevations above sea-level can be converted to a timescale. Rebound values (R) of the Schmidt hammer are correlated with the altitude and the degree of rock weathering can be estimated for each site. Eight sites with boulder-beaches and nine sites with rocky shores have been analysed. For boulder-beaches correlation-coefficients of 0.82-0.97 for weathering values (R) and the elevations above sea-level were obtained. For the rocky shores these values were calculated to 0.75-0.97. This method has applications in both geomorphology and archaeology. For example, a deep layer of weathered dolerite in the Nordingrå region, which previously has been regarded as a post-Weichselian formation, can be shown to be of pre-Weichselian origin. Several archaeological applications are also mentioned in the paper.  相似文献   

空气潜孔锤跟管钻进技术与应用   总被引：1，自引：1，他引：0       下载免费PDF全文

赵建勤  李子章  石绍云  王勇  罗宏保 《探矿工程》2008,35(7):55-59

跟管钻进技术已发展成为对付复杂地层钻进的一种有效方法,主要介绍空气潜孔锤跟管钻进技术、SP系列跟管钻具的特点以及空气潜孔锤跟管钻进技术在地质灾害、水电建设、城市高层建筑地基处理、公路、铁道建设工程等复杂地层钻进的应用。  相似文献   

城市软土地基组合锤法强夯施工振动效应研究     

刘超  梁海安  程新俊  聂佩江  李俊豪  吕毅 《震灾防御技术》2021,16(2):381-390

为研究组合锤法强夯振动对周边场地环境的影响,对南昌市某软土地基进行现场原位试验。考虑距强夯点的距离、振动方向及锤击次数的影响,在各监测点分别布置水平东西、南北向和竖向振动传感器。结果表明:采用组合锤法进行地基强夯施工时,场地竖向振动是需重点监测的内容,振动响应随监测点与强夯点距离的增大而减小;距强夯点50 m范围处地面振动速度衰减至0.2 cm/s以下,可根据地面振动速度确定安全施工范围;地面加速度受锤击次数的影响较大,且水平向加速度对锤击次数的敏感性略高于竖向,锤击次数对地面水平向振动的影响不可忽略;基于试验数据和波源振动理论建立的振动加速度衰减模型综合考虑了距强夯点的距离、振动方向和修正系数（锤击次数的影响）,经算例验证具有较强的适用性,可为同类场地采用组合锤法强夯施工提供参考。  相似文献   

空气潜孔锤钻进技术在铝土矿钻探施工中的应用试验     

刘建华  魏淑华  徐爱臣  柴世刚  刘亚南  李国锋  李大鹏 《探矿工程》2013,40(1):28-30

详细介绍了在铝土矿区进行空气潜孔锤钻进技术的应用试验。试验结果表明：该技术与普通双管钻进技术相比平均时效提高5.1倍,最高时效可达15.33 m。通过试验得出了几点认识,为在铝土矿区进一步推广应用空气潜孔锤钻进技术积累了实践经验。  相似文献