岩溶塌陷地表稳定性分析及工程地质分区

研究目的:岩溶地表塌陷是近20多年来较频繁出现的不良地质问题,铁路工程不良地质勘察规程中对地表塌陷主要因素综合评价,强调岩溶固有特性和固定的地质因素,缺少人类生产活动对水环境影响这一最活跃、最现实的因素,因此不稳定地区范围在主观因素影响下划分比较宽松,使工程造价抬升。本文意在设计中病害工点划定合理,有效控制工程造价。研究方法:通过对地表塌陷机理,特别是潜蚀成因的研究,对塌陷成因的分析,充分重视人为因素在塌陷时空中的重要作用。研究结果:通过研究认为,近期地表塌陷除少量是地质时期,历史时期的产物之外,大量都是与人为因素有关的同期,甚至是同步的产物,没有人为活动,地表塌陷是有限的。笔者认为:根据人为因素结合岩溶及地质的固有因素进行地表稳定性分析,划分稳定区、相对稳定区、不稳定区、塌陷区,按其稳定性、危害程度有针对性、有重点地整治。研究结论:通过研究、讨论,将铁路勘察规程进一步补充完善。避免出现遗漏不良地质或扩大化现象。

Analysis of Stability of Subsidence Surface in Karst Area and Zoning for Engineering Geology

Research purposes: Subsidence in karst area is an unfavourably geologic problem that has been occurred frequently over 20 years.The natural characteristics of karst and fixed factors of geology are focused in overall assets to main causes for subsidence stipulated in Regulation of Unfavourable Geologic Survery for Railway Engineering,but the most active and actual factors influencing water environment by the production activities of human are less focused.Therefore,zoning unstable zone is loose under personal object factors and makes construction cost rising.The purposes of this paper are to rationally zone disease working site in design so as to control construction cost effectively.Research methods:The analysis and research were made on the mechanism and cause for subsidence,especially the cause for submarine erosion.It required paying attention to the important effects of personal factor on subsidence.Research results:It is believed through research that the most recent subsidence are the outcomes related to personal factor in the same period,at least a synchronic outcome,except a few of them are the outcomes of geologic age and historic period.There is less subsidence without man-made action.The author beliveves the engineering geology shall be divided into stable zone,relative stable zone,unstable zone and subsidence zone according to personal factor and natural factor of geology.The treatment shall be carried out to them pointedly and focally according to their stability and disaster level.Research conclusions:Based on study and discussion,it is believed Railway Survey Regulation will be supplemented and improved in order to avoid phenomena of dismissing unfavourable geology or broadening the scope of unfavourable geology.