Sudden surface collapse disasters caused by shallow partial mining in Datong coalfield,China

Numerous sudden surface collapses induced by shallow partial mining in the Datong Jurassic coal seam have caused fatalities, significant property losses and brought about harmful results to the environment. By introducing efficient pillar widths and using the Voronoi diagram, irregular pillar stability can be estimated rationally. Theoretical analysis and numerical simulation demonstrate that the failure of a single pillar increases the load on surrounding pillars. If the magnitude of the transferred load is sufficiently high, the adjoining pillars will also fail in a chain reaction. This can be interpreted by the merger of inner stress arches combined with the external stress arch. In this paper, the evolution mode of sudden surface collapse caused by shallow partial mining is proposed and has been verified by ‘similar material simulation.’ Finally, the potential of sudden surface collapse is determined and an example of collapse prediction and prevention of surface building damage with relocation is given.     

江苏徐州岩溶塌陷及其防治对策

徐州地区碳酸岩地层分布较广,岩溶较为发育。由地下岩溶所引起的地面塌陷地质灾害频发。本文分析了徐州地区岩溶发育条件、发育特征、分布规律和区域地质环境、人为因素等,对可能引起的地质灾害进行了研讨和预测。初步探讨了徐州岩溶塌陷地质灾害的防治措施和对策。     

明代(公元1368—1644年)钱塘江河口潮灾时空分布及其影响因素

钱塘江河口是世界著名强潮河口。基于历史文献资料,系统梳理考证了明代(公元1368—1644年)钱塘江河口潮灾记录,分析了潮灾的空间、时间分布特征:(1)北岸潮灾远多于南岸,海门以上河口段与海门以下河口段潮灾次数基本持平,但均少于河口湾段。(2)潮灾在南北两岸的空间分布上,存在转移与变迁,由此导致两岸分别存在明显的平缓期—爆发期—平缓期交替,但平缓期与爆发期的时长并不固定。(3)潮灾强度变化与潮灾频次分布有较强关联,高强度潮灾多发于潮灾频发期。结合历史气候、江道地形等自然环境背景,探讨了影响潮灾时空分布的要素,认为钱塘江潮灾发生的频次及规模大小与流域内干湿变化及历史气温升降有明显关联,而历史极端潮灾则常是多种要素耦合的结果。     

青海省明长城濒危遗址（湟中段）土体工程性质与保护措施

明长城遗址受自然地质作用、人为活动以及环境等因素的多方面作用,破坏相当严重．以青海省湟中县明代长城遗址保护工程为依托,实地调察了遗址发育的病害,通过室内测试分析,全面掌握了遗址土体工程性质,有针对性地提出裂隙填充注浆、裂隙注浆、土坯砌补、注浆回填、锚杆锚固等加固措施．从一期工程的加固效果来看,所用方法对夯土类长城加固具...     

四川锦屏山地区新构造运动及地质灾害

文章通过对四川锦屏山地区区域地质概况、河流阶地、第四纪断层及老断层新活动、地震活动的研究,认为该地区自更新世以来,新构造运动较为强烈,由此造成的地质灾害主要有滑坡、崩塌、泥石流等。     

辽宁省建平县地质灾害调查与防治

建平县日益突出的地质灾害问题已经成为制约当地社会经济和可持续发展的不利因素。该县地质灾害的有效治理已是摆在建平县政府和人民面前的首要任务。在对建平县地质灾害调查的基础上，提出了该县防治地质灾害的措施和恢复自然生态环境的建议。研究认为，防治地质灾害和恢复自然生态环境的根本途径在于，加大综合治理力度和大力提倡植树种草。     

渝东北典型盆缘山区高位崩滑灾害风险评价

研究区位于重庆市巫溪县下堡镇内,属渝东盆缘山区,地形切割强烈,地质环境复杂,地质灾害频发。为了研究高陡峡谷区地质灾发育分布规律、风险区划,文章选取高程、坡度、坡向、工程地质岩组、距水系距离及距褶皱距离因子做为地质灾害易发性评价的影响因素,基于ArcGIS平台,利用信息量模型,定量评价了巫溪宁桥片区高陡峡谷区高位地质灾害的易发性,评价模型与地质灾害分布空间契合度较高,评价结果可信度较高。再结合易损性评价对研究区进行了地质灾害风险评价,最终得到研究区地质灾害风险评价模型。为该区域地质灾害防治提供了科学依据,同时对同类高陡峡谷地区地质灾害风险性评价及地质灾害防治具有借鉴意义。     

Flood, drought and typhoon disasters during the last half-century in the Guangdong province, China

In this paper, we present the changing properties of losses due to occurrences of droughts, floods and typhoon disasters in the Guangdong province, a comparatively economically prosperous province in the south China. Influences of typhoon activities on droughts and floods are also analysed. Results based on extensive and thorough investigations indicate that (1) generally, Guangdong province is both humid and warm; however, in recent decades, the negative impacts of droughts seem to be enhancing, which is proved by increasing drought-induced economic loss. In this sense, considerable importance should be attached to droughts, but not solely to floods, in the Guangdong province; (2) low-lying terrain of the Guangdong province makes this region easy to be influenced by flood inundation. Moreover, highly urbanized areas are mostly located in the low-lying areas. Flood-induced loss was increasing before 1990s and is decreasing after 1990s, and this should be attributed mainly to seasonal shifts of precipitation changes and enhancing human mitigation to flood disasters; (3) typhoon activities often inflict considerable loss on the economy of the Guangdong province. Moreover, flood events in the study region are mostly the results of typhoon activities. Flash floods, strong wind and storm surge accompanying typhoon activities are the major factors intensifying the negative impacts of the typhoon disasters.     

Social differentiation and the long-term origin of disasters

To explain both origin and outcome of disasters (natural, technical, and war-borne), as well as social action during disasters proper, a macrosociological model of internal causation is introduced (PERDUE). It consists of six stages of possible, and of most likely paths of social change between these six (Peace is founded, Everyday routine, Rising class struggle, Disasters strike, Unconditional surrender of collective defence, and Evaporation of common values). The stages are developed by making use of three dimensions of social change (rapidity, radicality, and rituality), and described.     

江苏淮安市地质灾害现状及防治措施研究

概述了研究地质灾害现状及防治措施的意义,阐述了淮安市地质灾害种类、现状及地质灾害易发区的综合划分,对淮安市的地面沉降、滑坡等重点地质灾害提出了相应的防治措施。     

黑龙江地质环境特征与主要地质灾害

黑龙江省地域辽阔,地质环境条件复杂,受自然和人为因素的综合作用,产生了一系列地下水下降、地下水污染、地面沉降、采空塌陷、崩、滑、流及土地"三化"等环境地质问题。在哈尔滨市、大庆市形成了面积分别为380km2和5000km2地下水开采降落漏斗;在鸡西、鹤岗、双鸭山、七台河四个煤炭城市形成了551km2的采空塌陷区;在松嫩平原形成了面积573752.1hm2沙化区和386486.79hm2盐渍化区。     

枣庄岩溶塌陷形成机理与致塌模型的研究

渗压效应是指由于降雨入渗补给岩溶地下水,而对盖层土体产生的综合作用,包括静水增荷效应、垂直渗透效应、吸水软化效应及负压封闭效应。渗压效应致塌机制是多年持续采水区降落漏斗中心部位岩溶塌陷的主要力学机制。本文根据普氏理论及极限平衡理论分别建立了内部塌陷阶段临界土洞的高度表达式及地表塌陷阶段的渗压效应致塌力学模型,并用表达式及模型对枣庄市的岩溶塌陷进行了验证分析与评价,分析结果与实际塌陷情况符合较好,建立的表达式与模型基本上反映了该地区岩溶塌陷的形成机理。     

Karst collapse in cities and mining areas,China

Karst collapse is a dynamic geological phenomenon, in which the rock mass or deposits overlying the karstified zone subsides down along the karst cavity, resulting in a collapse pit or sinkhole. After discussing the typical examples of collapse emerging in the karst cities and mines in provinces and regions of South China, such as Guangdong. Guangxi, Hunan, Hubei, Zhejiang, Yunnan, Guizhou, and Jiangxi, it is considered that human activities of economy and production have become a major effect in causing karst collapse. Man-made collapses make 66.4 percent of the total, whereas natural ones 33.6 percent. Most of the collapses occurred to the area with soil overburden (96.7 percent), only a few in areas of bedrock overburden (3.3 percent). The karst collapses have a close relationship with the extent of karst development, the character and the thickness of overburden, and the dynamic condition of underground water. Collapse usually occurs in those parts of an area that are more intensely karstified, with soil thickness less than 5 m and a high amplitude of water table fluctuation. Many kinds of mechanical effects are caused by pumping or draining on the overburden and destroying its equilibrium, leading to the collapse. These effects included the support loss and loadadded effect, penetrating suffusion, gas explesion, water-hammer, suction pressure erosion, and liquatienal effects. The collapses are the result of varied comprehensive effects, particularly the support loss and load-added, and penetrating suffusion.