【摘要】 基于高填土涵洞(管)减载基本原理,结合明洞结构自身特点,构建了土工格栅减载的明洞结构力学模型.利用朗肯土压力理论,推导出了铺设单层土工格栅减载结构土压力计算公式,可直接求解格栅顶部土柱土压力、格栅底部土体支撑力和明洞顶土压力.对多层土工格栅结构类型,推导了其明洞顶土压力的计算表达式.实际场地明洞试验证明了本文方法的准确性及土工格栅减载措施的良好效果,可满足实际土工格栅减载工程一般要求.同时对影响减载效果的各参数敏感性进行了分析,讨论了格栅刚度、变形、层数、铺设高度和锚固长度在实际工程减载过程中的设置.更多还原

【Abstract】 A mechanical model with geogrid reinforcement was established for open cut tunnel.The formula of earth pressure exerting on single layer geogrid was derived via the theory of Rankine earth pressure.The earth pressure of soil column on the top of the geogrid,the support effect of soil under the geogrid and the earth pressure on the top of the open cut tunnel were solved.According to multiple layer geogrid,the formula of earth pressure was derived.A field experiment on an open cut tunnel demonstrates that the calculation method is accurate and the measure of geogrid load reduction is effective,which means that the geogrid load reduction can meet the general requirement.Sensitivity analyses were performed to study the main factors such as stiffness,deformation,layers laying height and anchorage length of geogrid.更多还原