滑坡灾害预测研究概况

本文以文献资料为依据,阐述了滑坡灾害的严重性、人类活动与滑坡灾害的伴生性,并从减轻灾害的角度,分析了滑坡灾害空间预测和长时间预测的重要意义及其研究趋势。     

突变理论在工程地质中的应用

本文说明了突变理论应用于工程地质中的一般方法。着重通过实例介绍尖点突变理论在工程地质中的应用现状,其中包括用突变理论评价层状结构斜坡、地下洞室的顶板冒落及活断层的稳定性,以及斜坡失稳的时间预报等问题。同时对其应用前景作了展望。     

佛顶山钙铬榴石分布特征及其找矿意义

本区钙铬榴石含钙铝榴石分子，两者组成类质同像系列矿物，颜色和透明度随成分变化而变化。目前找到的钙铬榴石成翠绿色十分美丽。但是，透明者少，粒度均小于４ｍｍ，达不到宝石级标准。但埋于坡积层中的含钙铬榴石铬透辉石岩的转石风化强烈，钙铬榴石易于脱出，晶体保存完整，采选容易，是寻找宝石的理想地区。     

A theoretical investigation of bed-form shapes

The deformation of movable boundaries under the action of an applied turbulent shear stress is well known. The resulting bed forms often are highly organized and nearly two-dimensional, which makes them an intriguing focus of study considering that they are generated in both steady and oscillatory turbulent flows. Many past studies share a common approach in which an infinitesimal perturbation is prescribed and the resulting growth or decay patterns are examined. In this approach, the bed forms are usually sinusoidal and the perturbation analysis does not provide a theoretical prediction of equilibrium bed-form geometry. An alternative approach is suggested here in which the forcing terms (pressure and stress) are prescribed parametrically and the governing equations are solved for the flow velocity and the associated boundary deformation. Using a multilayered approach, in which the bottom boundary layer is divided into a discrete, yet, arbitrary number of finite layers, analytical solutions for the horizontal current and bed profile are derived. The derivations identify two nondimensional parameters, p₀/u₀² and ₀/kh₀u₀², which modulate the amplitude of the velocity fluctuations and boundary deformation. For the case of combined pressure and stress divergence anomalies, the magnitude of the front face and lee slopes exhibit an asymmetry that is consistent with observed bed forms in steady two-dimensional flows.Responsible Editor: Jens Kappenberg     

GPS滑坡监测系统在铁路桥桥墩稳定性监测中的应用

结合对铁路桥桥墩的实际监测应用，介绍了GPS滑坡监测系统的工作原理和性能特点，阐述了现场安装过程中的许多重点问题及其对监测效果的影响，并结合实际测量数据论证了该系统应用于滑坡监测的可行性和优势所在。     

Seismic hazard assessment for derivation of earthquake scenarios in Risk-UE

The main features of the Risk-UE project approach to assessing the ground-shaking (and related hazards) distribution within urban areas are described, as a basis for developing seismic damage scenarios for European cities. Emphasis was placed in the project on adoption of homogeneous criteria in the quantitative treatment of seismicity and in constructing the ground-shaking scenarios, despite wide differences in amount and quality of data available for the cities involved. The initial steps of the approach include treatment of the regional seismotectonic setting and the geotechnical zonation of the urban area, while the hazard assessment itself takes the form of both a deterministic analysis, and of a probabilistic, constant-hazard spectra analysis. Systematic 1D site response analyses were used, mostly in the softer soil zones, to modify (when needed) the obtained ground motion maps. Earthquake induced hazard effects, such as liquefaction and landsliding, are also briefly dealt with at the end.     

江苏镇江焦山索道上站滑坡治理中技术方法的应用

镇江市是江苏省滑坡地质灾害较为严重的城市,其地质灾害防治工作开展较早,积累了一定的防治管理经验。而焦山索道上站滑坡治理工程是多种滑坡治理技术方法和措施的综合应用,通过混凝土抗滑桩、锚索、锚杆、排水以及挂网喷播复绿等技术方式和措施的应用,成功地完成了焦山索道上站的滑坡治理工程,为镇江市其他滑坡地质灾害的治理提供了一定的参考借鉴作用。     

Residual strength of slip zones of large landslides in the Three Gorges area, China

Slip zones of the large landslides in the Three Gorges area are commonly composed of fine-grained soils with substantial amount of coarse-grained particles, particularly gravel-sized particles. In this study, residual strength of the soils from slip zones of these landslides were examined in relation to their index properties based on a survey of 170 landslides. It was found that laboratory-determined residual friction angle using gravel-free fraction of the disturbed soils from the slip zones was closely related to clay content, liquid limit and plasticity index. On the other hand, in-situ residual friction angle of these soils (i.e. including gravel fraction) showed very weak correlations with clay content and Atterberg limits, but was largely dependent on gravel and fines (clays + silts) contents, increasing with gravels and decreasing with fines, and displayed strong linear correlation with the ratio of gravel to fines contents. These observations indicate that among the index properties, clay content and Atterberg limits can be used to estimate residual strength of the soils finer than 2 mm, but they are not appropriate evaluate the residual strength of the soils containing considerable amount of gravel-sized particles. For the latter, particle size distribution (particularly the ratio of gravel to fines contents) appears to be a useful index. Additionally, it was found that there was no identifiable correlation between relative abundance of individual major clay minerals and residual friction angles of both gravel-free fraction of disturbed and in-situ soils, suggesting that influence of clay minerals on residual strength of these soils can not be simply evaluated based on their abundance.     

The geotechnical effects of long human habitation (2000< years): Earthquake induced landslide hazard in the city of Zefat, northern Israel

This work studies the effects of long human habitation on site geotechnical conditions. It is focused on the city of Zefat that is located on the borders of the Dead Sea Transform in northern Israel. The city of Zefat, suffered severe damage and loss of life in historical earthquakes, as a consequence of earthquake induced landslides (EILS). In this work we evaluate the current EILS hazard for the city of Zefat using a GIS-based regional Newmark analysis, with calibration of the calculated Newmark displacement (representing EILS hazard) using maps of field evidence and historical documents testifying to slope instability that occurred in historical earthquakes.

We found that the core city of Zefat is built on a layered anthropogenic material, few meters deep which, was deposited as a result of more than 2000 years of human habitation. The anthropogenic material is mechanically weak, susceptible to slope failure and to amplification of seismic-shaking. It is responsible for the city's devastation in historical earthquakes and it is the source for the current high seismic hazard as well.

Our model shows that earthquakes of magnitudes (M_w) 5, 6 and 7 at distances of up to 10 km, 50 km and more than 100 km, respectively, are likely to induce landslides in the core city of Zefat. The current engineering status of the city is poor, and as a consequence severe damage and loss of life are expected in future earthquakes due to EILS, unless major engineering efforts are made. Cities in the Eastern Mediterranean with comparable long habitation histories (e.g., Jerusalem, Tiberias, Nablus, Amman) are expected to have similar geotechnical problems in their old sections and are advised to take appropriate engineering steps to reduce damage and loss of life in future earthquakes.

Evaluation of historical earthquake magnitudes based on reported local-damage may, however, lead to overestimated magnitudes where the damaged sites are built on anthropogenic talus (a common setting in the vicinity of the Dead Sea Transform).     

攀钢石灰石矿H3滑坡研究

四川攀钢石灰石矿曾发生多次大规模滑坡,给矿山生产造成巨大损失。以其中规模较大的Ｈ３滑坡为研究对象,分析探讨该边坡的失稳原因,建立边坡失稳概念模型,并用离散单元法论证该边坡概念模型的合理性。