岩溶地面塌陷区地下水监测方法探究——以广东肇庆地区某自然村为例

岩溶地面塌陷是南方地区主要地质灾害之一,对岩溶塌陷区进行有效的监测预警十分必要。以广东肇庆地区某自然村为例,通过对研究区地质背景、已发岩溶塌陷情况、形成机理及演化过程进行分析,查明该研究区在地下水下降时,上覆土体在岩溶水与孔隙水所产生的压强差或真空负压作用下会发生岩溶塌陷,岩溶塌陷属吸压-陷落模式;采用间接监测法在该岩溶地面塌陷区设置监测孔2个,分别对2014.12.28-2015.12.08期间的岩溶地下水和底部土层之上的砂层孔隙水进行监测,并提取水位变化速率、水力梯度的数据范围,对相关数据进行对比分析,结果显示:研究区地下水水位变幅及波动速率未有明显异常值,底部土层水力梯度远小于临界水力梯度,岩溶塌陷水动力条件属于正常值范围,该时段内无新发岩溶塌陷灾害。研究可见,对地下水位进行长期监测,并积累长系列数据,可为日后监测预警的阈值提供依据。     

论岩溶地下水位对岩溶塌陷形成的控制作用——以山东枣庄市岩溶地面塌陷区为例

枣庄市是山东省岩溶地面塌陷的主要发育地区之一,岩溶地面塌陷灾害连年发生,给当地的生产、生活造成巨大经济损失,已成为该地区经济发展的制约因素。本文对该地区的地质条件、塌陷现状及岩溶地面塌陷的分布规律进行了分析归纳,从中得出枣庄岩溶地面塌陷容易发生在:在第四系厚度为5～10m的地段,时间为每年4～9月份,地势低洼处。本文从压力差的角度,在简要分析岩溶管道的发育程度、盖层条件的基础上,分析了地下水位在枣庄地面岩溶塌陷的控制作用,并以此为依据简要提出了几个防治建议。     

枣庄岩溶地面塌陷机理研究

过量开采岩溶水会导致岩溶地面塌陷,枣庄则是全国岩溶地面塌陷比较严重的地区之一,塌陷已对当地的居民生活和经济建设造成了巨大的危害。根据大量的勘察资料和地下水动态监测资料,研究了枣庄地区奥陶系碳酸盐岩岩溶发育特征,探讨了岩溶地面塌陷的形成机理,岩溶裂隙和上覆土层的性质和厚度是岩溶地面塌陷的先决条件,地下水位大幅度升降引起的物理地质作用是塌陷的主要动力来源,震动和水位突变是重要的诱发因素。     

河北唐山市区岩溶塌陷发育特征及成因机理探析

唐山是我国北方岩溶塌陷地质灾害多发地,1976年唐山大地震以来,岩溶塌陷已发生多起。在分析岩溶发育现状的基础上,描述了该区的岩溶发育特征,进而研究了岩溶塌陷的成因机理。研究认为,采矿活动和过量开采岩溶地下水是造成岩溶塌陷的直接诱因,它直接改变了地下水动力条件,局部形成了水位漏斗;地面建筑物的重力荷载、煤矿透水灾害和地震等将直接导致岩溶塌陷地质灾害的发生。据此提出了较为具体的防治措施。     

枣庄岩溶塌陷形成条件及主要影响因素

近年来枣庄市岩溶塌陷频繁发生。通过野外地质调查、现场采样和室内试验相结合的综合手段,对该区的岩溶塌陷覆盖层进行系统地取样并进行深入细致的实验及分析,论述了覆盖层特征对该区岩溶塌陷的影响;运用宏观调查、细观测量和微观分析相结合的研究方法详细论述了地质构造对岩溶塌陷的影响;结合历年水文动态资料、地下水开采量等论述了地下水活动对岩溶塌陷影响。综合认为,地层岩性、覆盖层性质、构造因素是枣庄岩溶塌陷频繁发生的内因,而超量开采地下水则是外部诱发因素。     

矿坑排水与岩溶地面塌陷的关系

浙江省某岩溶矿区南部洼地先后发生6处地面塌陷,引发了当地居民的恐慌。矿区排水是唯一地下水开采活动,为分析塌陷区与矿区之间的水力联系,遂在研究区全面布置地下水监测系统。通过对比分析观测水位、矿坑排水量及当地降雨量数据,探讨地面塌陷与矿区排水之间的关系及其潜在成因。研究表明,研究区岩溶地下水动态变化整体保持一致,受降雨、矿坑排水等综合因素影响。北部矿区和南部洼地存在岩溶连通管道,两者在雨季水力联系微弱、旱季水力联系密切。经长期径流潜蚀作用,〖JP2〗导致区内地面塌陷区灰岩顶板岩溶发育处上覆土层出现土洞,当矿区排水量急剧增大时,南部洼地岩溶水位大幅度下降,使得土洞中出现负压、上覆土层所受浮托力降低、孔隙水与岩溶水补排关系改变,在多种效应共同作用下,土洞最终形成地面塌陷。      

安溪县剑斗镇湖丘角落地面塌陷成因分析

2002年6月30日，福建省安溪县剑斗镇湖丘角落发生地面塌陷，造成房屋倒塌，人员伤亡。通过对该区环境地质条件和地面塌陷分布规律的分析与研究认为：塌陷区内岩溶裂隙发育是形成地面塌陷地质条件；矿井对地下水的疏干这是导致地面塌陷或不均匀沉降产生地裂缝的内在动力；深部及周围石灰岩矿的开采，为岩溶洞隙充填物提供了被搬运带走的空间，使得潜蚀作用可以不断地向上扩展；强降雨是加速岩溶区地面塌陷的外部动力。     

湘桂铁路二塘车站路基岩溶塌陷成因与防治对策

湘桂铁路二塘车站高铁区段1996-2016年间发生岩溶塌陷险情27起,虽经过多期悬挂式帷幕注浆整治,但塌陷问题仍是行车安全的极大隐患。通过资料收集、场地野外调查、岩溶地下水气压力长期监测站的监测资料分析,细化了研究区的地质构造、岩溶水文地质条件及岩溶发育特征,从地质结构、岩溶地下水动力特征等方面分析,认为岩溶塌陷形成的成因为临桂地区房地产基坑开挖抽排水影响岩溶地下水水位变化,造成基岩面上覆土体的潜蚀,形成土洞,进而发展至地面形成塌陷坑。针对铁路运行段地下水位埋深具承压性,隐伏溶洞充填率高的复杂岩溶地质条件以及注浆压力的限制,提出加强基岩面上覆土层抗渗强度、管控岩溶地下水降深的岩溶塌陷防治对策。     

重庆中梁山岩溶地面塌陷特征及形成机理

通过详细调查重庆中梁山地区的岩溶地面塌陷灾害情况,分析出该区地面塌陷特征及形成机理。结果表明:岩溶地面塌陷主要分布在嘉陵江组中的地势低洼处、断层和溶槽处,多发生在降雨量大和地下水水位陡降时期,是自然因素和人类活动共同作用下的结果,数量较多,以土洞型为主;其致塌的力学机制以真空吸蚀作用和潜蚀作用为主,多种作用为辅;在具备岩溶塌陷发生的地质条件下,隧道建设过程中的强排水、降雨和村级公路修建与运营过程中会诱发岩溶地面塌陷的发生。根据岩溶地面塌陷的致塌力学机制和诱发因素,提出预防降雨形成的地表水过度聚集,隧道建设避免地下水陡降,村级公路和隧道选址避开岩溶发育区域等措施,以防止岩溶地面塌陷发生。      

广东英德沙口镇岩溶地面塌陷发育特征及形成机理分析

近年,广东省粤北山区隐伏区岩溶地面塌陷日益增加,直接影响人民生产生活。英德市沙口镇某村地质环境复杂,第四系覆盖层厚度薄,底部卵石层与下覆天子岭组灰岩直接接触,溶洞与断层破碎带发育,溶洞与溶洞间连通性较好,岩溶地面塌陷地质灾害严重。在综合分析沙口镇某村地质环境条件基础上,从内、外两方面因素,对岩溶地面塌陷发育特征及形成机理进行分析,认为在长期地下水位波动、潜蚀及淘蚀等作用松散盖层土体颗粒流失形成土洞,地表水与地下水强烈交替形成正负压力等作用下,土洞上部盖层发生塌陷。研究结论为科学制定岩溶地面塌陷防治方案提供依据。     

枣庄市地下水动态变化特征研究

枣庄市以岩溶地下水为主要供水水源,多年的超采造成了十里泉及丁庄主要岩溶水源地下水水位大幅度下降,并诱发了地下水污染、岩溶地面塌陷等严重的环境地质问题。根据枣庄市岩溶地下水21年的监测资料,揭示了枣庄市岩溶地下水水位动态特征。岩溶地下水水位呈现季节性和多年变化特征,其中,岩溶地下水水位季节性变化特征与降水量密切相关,多年水位变化受降水和开采量的综合作用的影响。     

枣庄市十里泉电厂第三水源地地下水位年变幅灰色预测

该文依据往年地下水位监测数据,通过灰色系统理论的预测模型,对枣庄十里泉电厂地下水位年变幅做出预测,分析了岩溶塌陷发展趋势,为由水动力因素引起的岩溶塌陷地质灾害提供防治依据。     

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。     

Comprehensive analysis and quantitative evaluation of the influencing factors of karst collapse in groundwater exploitation area of Shiliquan of Zaozhuang, China

Karst collapse is a type of complicated environmental and geological hazard that can be caused by many factors: natural factors, such as rainfall, and human activities, such as overpumping of groundwater. Therefore, it is important to make a comprehensive analysis and evaluation on karst collapse risks and impacts of the influencing factors of karst collapse. However, how these factors affect karst collapse is still a problem, which has not yet been well solved. Taking the karst collapse in groundwater exploitation area of Shiliquan of Zaozhuang, China, as the example, and based on the comprehensive analysis of the formation rule and mechanism of karst collapse in this area, this paper mainly employs Quantification Theory to make a quantitative analysis and evaluation of various influencing factors of karst collapse in the groundwater exploitation area of Shiliquan of Zaozhuang. It thereby determines the impact of different influencing factors on karst collapse strength, and identifies the dominant and minor factors that affect the karst collapse. It also provides some criteria for the prevention of karst collapse and protection of karst water resources and environment.     

Comprehensive fuzzy evaluation model and evaluation of the karst collapse susceptibility in Zaozhuang Region, China

Karst collapses in Zaozhuang area are the typical karst collapses induced by groundwater over-pumping in north China, which lead to severe economic loss and negative societal influence. Based on the comprehensive analysis of all natural influencing factors and human influencing factors associated with karst collapse in the Zaozhuang Shili Spring Area, China, this paper establishes karst collapse susceptibility evaluation model by means of fuzzy mathematic method, in which the Quantitative theory method was firstly applied in determination of the factor weights. The karst collapse susceptibility evaluation model with 14 evaluation indicators can be effectively used for quantitative evaluation on the karst collapse susceptibility. So, an analysis and evaluation on the karst collapse susceptibility of Zaozhuang Shili Spring Area is completed by means of karst collapse susceptibility evaluation model. The karst collapse area of Zaozhuang region is divided into very high susceptibility area, high susceptibility area, medium susceptibility area and low susceptibility area, which account for about 6.3, 5.2, 10.4 and 78.1 % of the total karst area and the karst collapse susceptibility evaluation map of Zaozhuang Shili Spring Area is completed. The results above will be helpful for the strategic planning and decision-making processes associated with exploitation of karst water resources and with prevention and control of karst collapse hazards of this region.     

The karst collapses induced by environmental changes of the groundwater and their distribution rules in North China

China, whose distribution area of karst region reaches about 3.63 million km², is one of the countries that have the widest karst collapse development. In modern-karst collapses, the karst collapse induced by water environment is an important type in karst collapses of North China. This paper completed a systematic study on the relations between groundwater environmental transformation and karst collapses and their distribution rules in northern China and found out that the karst collapses in northern China are closely related to the change of groundwater environment, which increased along with the declining groundwater levels and increasing hydraulic gradient. Meanwhile, it was also found that in all cases of collapse caused by underground-environmental change of northern China, pumping collapses in urban areas appeared to be the commonest and strongest among modern-karst collapses with 20 regions and 796 mining pits in total, which account for 30.7 and 58% of artificial collapses, respectively, followed by collapses that were induced by mining draining and inrushing water with 33 regions and 282 mining pits, accounting for 20.4%. In addition to the conditions listed above, there were also a few water caving collapse and leakage collapse.     

Evaluation of karst collapse risks induced by over-pumping and karst groundwater resource protection in Zaozhuang region,China

Based on the comprehensive analysis of factors influencing karst collapse in the Zaozhuang Shili Spring Area, China, this paper establishes a karst collapse risk evaluation model by means of the fuzzy comprehensive evaluation method. Application of the model led to division of the study area into very high risk area, high risk area, average risk area and low risk area; therefore, the karst collapse risk evaluation map of Zaozhuang Shili Spring Area is completed. As preventive measures of karst collapse, the different karst water resource protection areas of Zaozhuang Shili Spring Area are established, and the map for karst water resource protection area of Zaozhuang Shili Spring Area is compiled. The results will be helpful for the strategic planning and decision-making processes associated with exploitation of karst water resources and with prevention and control of karst collapse hazards of this region.