建筑工程中膨胀土浸水软化及承载力试验

工程地基膨胀土浸水软化后,各项力学指标均有较大变化,承载力则明显衰减,设计和施工中应慎重对待.     

Plan curvature and landslide probability in regions dominated by earth flows and earth slides

Damaging landslides in the Appalachian Plateau and scattered regions within the Midcontinent of North America highlight the need for landslide-hazard mapping and a better understanding of the geomorphic development of landslide terrains. The Plateau and Midcontinent have the necessary ingredients for landslides including sufficient relief, steep slope gradients, Pennsylvanian and Permian cyclothems that weather into fine-grained soils containing considerable clay, and adequate precipitation. One commonly used parameter in landslide-hazard analysis that is in need of further investigation is plan curvature. Plan curvature is the curvature of the hillside in a horizontal plane or the curvature of the contours on a topographic map. Hillsides can be subdivided into regions of concave outward plan curvature called hollows, convex outward plan curvature called noses, and straight contours called planar regions. Statistical analysis of plan-curvature and landslide datasets indicate that hillsides with planar plan curvature have the highest probability for landslides in regions dominated by earth flows and earth slides in clayey soils (CH and CL). The probability of landslides decreases as the hillsides become more concave or convex. Hollows have a slightly higher probability for landslides than noses. In hollows landslide material converges into the narrow region at the base of the slope. The convergence combined with the cohesive nature of fine-grained soils creates a buttressing effect that slows soil movement and increases the stability of the hillside within the hollow. Statistical approaches that attempt to determine landslide hazard need to account for the complex relationship between plan curvature, type of landslide, and landslide susceptibility.     

Spatial predictions of geological rock mass properties based on in-situ interpretations of multi-dimensional seismic data

The article presents a statistical approach to characterize and predict engineering geological conditions in the up to 2000 m deep Faido tunnel and Gotthard base tunnel in Switzerland. Seismic investigations were conducted to improve the technology of interpreting seismic tomographic images. Overall, the goal of this study was to predict spacial maps of geological rock mass properties, such as, uniaxial compressive strength or total fracture spacing, by using up to six seismic features in combination, e.g., compression-wave and shear-wave velocities and dynamic Poisson's ratio. Self-Organizing Mapping (SOM), an artificial intelligent method, was used for the purposes of interpreting multi-dimensional geophysical attributes derived from seismic profiles of tomographic images along tunnel sidewalls. The SOM-method was applied in the Faido tunnel to delineate complex physical relations between the geological and seismic parameters. Then, the method was applied to predict geological properties around a segment of the Gotthard base tunnel with unknown geological–geotechnical conditions. The results illuminate that correlation analyses (pairwise parameter classification) are substantially less powerful than the SOM-method (multi-parameter classification) in order to interpret geological features from seismic in-situ data. Moreover, predicted spatial distributions of the total fracture spacing and the uniaxial compressive strength, for example, corresponded well with drill core and tunnel mapping results. The SOM-approach was a helpful tool for practitioners in predicting zones of instabilities and geological complexity during underground excavation processes of the Gotthard base tunnel. It is suggested to use such an interpretation method as decision support for purposes of sub/surface exploration and long-term geophysical monitoring of large-scale geoengineering projects, such as, disposals of nuclear waste and greenhouse gases or geopower plants for renewable energy (geothermal, biosoils).     

国内外地面沉降现状与研究

系统地介绍了国内外地面沉降的现状、引起沉降的原因、地面沉降的机理和地面沉降灾害预测与监测。特别针对上海地区随着大规模的城市建设产生的由工程环境效应引起的地面沉降及其监测与研究做了阐述。     

密集高层建筑群的工程环境效应引起地面沉降初步研究

地面沉降是常见的地质灾害之一。进入20世纪90年代以来,工程环境效应诱发的地面沉降已经成为上海地面沉降的新趋势。本文对密集高层建筑群诱发的地面沉降叠加效应及其施工对周围环境的影响展开初步研究,为控制密集高层建筑群诱发的地面沉降提供依据。     

地下管线普查监理工作方法及现状探讨

本文主要介绍了地下管线普查监理基本原理、工作方法、实施措施和目前地下管线普查监理现状，并对目前地下管线普查监理中存在的问题进行探讨。     

工程测量学的研究发展方向

本文首先概括了现代工程测量的发展趋势和特点，结合科研、教学和工程实践，对工程测量学科研究发展的三个主要方向即精密工程测量的理论技术与方法、工程的形变监测分析与灾害预报、工程信息系统的建立与应用进行了较深入详细的论述。最后，对工程测量学的发展进行了展望。     

构造地球物理学在孕震环境研究中的应用及其相关问题

简要论述了用构造地球物理学研究地震构造环境的基本思路、方法程序等,并从中长期地震预报及工程地震角度对这门交叉学科的产生背景、完善发展、科学意义与前景等相关问题进行了讨论.     

西部大开发与铁路建设

西部大开发将给我国中西部地区带来前所未的机遇, 而铁路建设正是遇到新的挑战。本文针对西部地区特殊的地质条件与地质环境, 详细探讨了在西部地区进行铁路建设可能遇到的问题, 为西部地区铁路建设提供了必要参考。     

区域稳定动力学研究(一)理论与方法体系

将区域稳定工程地质学推进到区域稳定动力学的研究层次上, 系统地构建了区域表层稳定动力学、区域浅层稳定动力学、区域深层稳定动力学、区域活动构造动力学、区域地震动力学、区域非稳定动力学过程及机制模式, 以及区域非稳定动力学环境下的地震工程效应、岩体失稳效应、场地失稳效应及建筑物抗断效应的综合研究及分析评价的区域稳定动力学研究的理论体系与方法体系。