天水市秦州区白家堡子滑坡特征与治理措施探析

以天水市秦州区白家堡子滑坡为研究对象,利用已有资料和野外实地勘察对其发育特征和物质组成进行系统的分析。明确了白家堡子滑坡属牵引式中厚层黄土—泥岩滑坡,滑体主要组成物质是黄土及部分全—强风化泥岩堆积层,滑体分上下两层滑面,滑面位于黄土—泥岩交界面或泥岩中,滑体缺少约束条件,较易变形失稳,长期处于活动状态。最后,根据白家堡子滑坡的特征,结合该区域的城市详细建设规划,初步提出白家堡子滑坡治理措施,为后期相邻滑坡的治理提供参考。     

Derivation of soil water retention curve incorporating electrochemical effects

Water retention of clayey soils with wide particle size distributions involves a combination of capillary and adsorbed layers effects that result into suction–saturation relations spanning over multiple decades of matric suction values. The present study provides a physics-based analysis to reproduce the water retention curve of such soils based solely on particle size distribution and porosity. The distribution of inter-particle pore sizes is inferred through a probabilistic treatment of the particle size distribution, which is then used, together with an assigned pore entry pressure, to estimate the inter-particle water volume at a given suction. The contribution to water content from adsorbed layers is also taken into account by considering the balance of electrochemical forces between water and clay material. The total water content is therefore found by summing up the contribution of inter-particle water, as well as adsorbed layers that form around clay particles and around the individual clay platelets. Comparisons with experimental results on nine different soil samples verify the capability of the model in accurately predicting the wide water retention curves without any prior calibration. Additional to capturing the essential features of the water retention curve with remarkable detail, the analytical model also provides insights into the relative contributions of capillary and adsorbed waters to the overall saturation at different suction regimes. Being based upon easily accessible information such as particle size distribution and void ratio, the model can therefore be considered as a substitute for costly and lengthy laboratory and in situ measurements of water retention curve.

     

The 2007 Fox Creek landslide,Peace River Lowland,Alberta, Canada

Fox Creek is a small tributary of the Saddle River, a tributary of the Peace River in northwestern Alberta. It has several dormant landslides with degraded scarps and grabens. A new, reactivated landslide on the north bank of the Fox Creek occurred on 5 May 2007. The landslide formed two major sliding blocks. A rapid translational block slide, it mobilized 47 Mm³ of displaced materials, blocked the creek, and made a natural dam with a maximum height of 19 m at the tips of the displaced blocks. The rupture surfaces of the 2007 landslide were within the advance phase glaciolacustrine sediments. The residual friction angles are about 10° similar to those of the previous landslides in the Peace River Lowland. Precipitation and snow melt prior to the landslide are likely triggers of the 2007 Fox Creek landslide. The farmlands on the crest of the river valley and timber resources were impacted. The current landslide dam in Fox Creek does not have any evidence of seepage downstream; it may last for many years. Eventually, the creek will overtop and erode the dam. The same cycle of actions, landsliding, damming, and erosion will continue in the foreseeable future.     

海底取样技术发展现状及工作原理概述 ——海底取样技术专题之一

从海底取样的意义和取样器的分类入手，阐述了国外海底取样器的发展现状及其工作原理，包括非可控式的冲击式，压入，射入式，吸入式；可控式的气动，液动冲击式，振动式，回转式等。     

Characterization of drying-induced deformation behaviour of Opalinus Clay and tuff in no-stress regime

The drying-induced deformation behaviour of Opalinus Clay and tuff, which are being investigated under international and local collaborative projects for nuclear waste disposal in Switzerland and Japan, was investigated under a no-stress condition in the laboratory to evaluate their generic susceptibility to the formation of excavation damaged zone. The cylindrical core samples of Opalinus Clay and tuff were prepared to a one-dimensional drying condition and submitted to an uncontrolled laboratory environment. The strain evolution, evaporative water loss and environmental entities, such as temperature and relative humidity, were recorded simultaneously and quasi-continuously. It was observed that the drying phase induced significant strain magnitude and damage in Opalinus Clay samples, which was evidenced by the formation of hairy cracks on the surface parallel to the bedding. On the contrary, the strain occurrences in tuff samples were relatively insignificant, and no tendency of cracking was observed. In addition, the quasi-continuous availability of volumetric strains was further used in poroelastic relation for the estimation of capillary suction evolution. The calculated results were validated with pore size distributions obtained from mercury intrusion porosimetry.     

在VB6.0环境下实现自动成柱状图

介绍了利用ADO技术访问数据库，同时对VB调用Windows API方面进行阐述。通过两者结合来实现钻孔自动成图，从而大大地提高野外工作效率。     

基于WebGIS的旅游景区空间智能评价系统研究

针对现有信息系统在空间智能评价方面的薄弱之处,运用WebGIS空间智能集成方法探讨旅游景区空间智能评价系统的设计和实现,从三方面提高了旅游景区评价系统的智能化层次:通过集成旅游景区网上调查问卷系统,提高了数据收集提取的智能化层次;通过集成旅游景区模糊综合评价模型、客流结构评价模型及旅游专家知识系统,增强了评价系统的半结构化智能推理功能;采用B/S C/S系统构架,并利用Web技术提高了人机交互界面的智能化。周庄景区案例评价结果显示,该系统原型的运行效果良好且智能化层次较高。     

河北平原地下水开发中的问题及可持续利用

河北平原是我国严重缺水地区，但在地下水开发过程中，引起了多种环境问题，如地下水位持续下降；地下水位降落漏斗不断扩大，地下含水层疏干；地面发生沉降及出现地裂缝；海、咸水入侵等等。作者从水资源、环境和社会经济的特点出发，提出实现水资源和社会经济可持续发展的对策：全面实施节水战略，努力实现工业、农业、居民生活、生态环境的高效用水，逐步建立起节水型社会；提高城市污水资源化利用率；利用海水、咸水、减少淡水用量；实施跨流域调水；保护水资源和改善水环境是缓解河北平原缺水和环境问题的重要措施。