高雄捷运大寮主机厂基地土壤液化潜能评估分析
Evaluation on soil liquefaction occurred at Taliao Main Depot of Kaohsiung MRT systems in Taiwan
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摘要: 以GPS/GIS/RS科技整合应用 ,对大寮主机厂基地区域环境与其工址地层特性进行汇整分析。由于高雄捷运系统大寮主机厂为捷运总部及行控中心所在 ,故针对大寮主机厂厂址基础地层的潜在灾害特性进行调查分析研究 ,很有必要。本研究采用NJRA法结合Iwasaki深度加权法 ,并特别考虑细粒料含量、地表最大加速度与填土静态加载等不同参数值的影响 ,对该厂址基础地层液化潜能进行评估。其结果显示邻近孔号EB -19&EB -2 7的区域具有较高液化潜能 ,只有当PGA =0 .18g且填土高度达 3m时 ,厂址地层液化潜能可降低至低度液化潜能范围 ;若以PGA =0 .3 3g作分析时 ,厂址各分区均属极高度液化潜能范围。本研究最后汇整大寮主机厂区环境特性与其基础地层灾害分析结果 ,建立该区域地层潜在灾害数据库系统 ,以利于判定厂区基础地层潜在土壤液化区的灾害空间分布趋势与掌握其特性变异 ,并为相关单位提供大寮主机厂基础地层土壤液化防治决策参考。Abstract: The characteristics of geoenvironment in Taliao Main Depot area are investigated by using GPS/GIS/RS technology.The Taliao Main Depot is assigned as the administrative center of KMRT system. The analysis on liquefaction potential of foundation soils in construction area should be conducted during the study.The evaluation on soil liquefaction of foundation is used to identify the region of potential soil liquefaction during earthquake occurred in this area.The criteria for liquefaction analysis of NJRA (1996) and Iwasaki method are selected on the basis of various parameters including fine grain soil content,PGA,and static load on foundation of soil.The results show that the areas adjoining boring sites of EB-19 & EB-27 are classified as those with high liquefaction potential.The filled soils with a height of 3 m under PGA=0.18 g increases the overburden pressure, but decreases the liquefaction potential of foundation soils for the Taliao Main Depot which has been classified as a safe region.However,if the PGA raises up to 0.33 g,the high potential liquefaction hazard region covers all the depot area filled by soils with a height of 5 m.Finally,the GIS technology integrated with the geoenvironmental characteristics of the studied area and the analysis of soil liquefaction has been used to build up the database systems of soil liquefaction occurred at Taliao Main Depot.The tendency of potential liquefaction studied by this project can offer a critical reference for the decision and its supporting systems applied to the construction of KMRT systems in the near future.