公路黄土暗穴临界稳定埋深回归的预测方法及其程序实现
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摘要
基于动力学基本方程,运用有限单元法(FEM)和NEWMARK隐式积分方法,对动荷载(FWD荷载)作用下路基下伏黄土暗穴动力稳定的临界埋深进行了弹塑性数值分析,考虑到人工截断边界上波反射对计算结果的影响,分别用传递边界和半无限单元来处理侧面和底面边界。在此基础上,对利用有限个数值分析结果进行不同洞径及位置暗穴临界稳定埋深的预测方法和步骤进行了分析,提出了一种基于洞径和中心距的双变量临界稳定埋深计算方法,并用VB6.0编制了计算程序LDMC。为验证程序的有效性,用3 m和5 m洞径的暗穴进行了对比分析,表明计算结果具有较高的精度,完全可满足实际工程的要求,同时指出了使用时应注意的问题。
First,according to the basic equation of dynamics,using FEM and NEWMARK implicit algorithm,an elastoplastic numerical analysis is made to analyze the critical burial depth of hidden holes in loess under the roadbed subjected to the dynamic load(FWD).In order to reduce the effect of wave reflecting on artificial boundary,transmitting boundary and semi-infinite elements are respectively used to treat the lateral and underside boundary.Based on the numerical analysis,a regression analysis method using finite numerical results of critical depth is developed;and the calculation program "LDMC" is compiled.Finally,a validity check of the program is made;and it is shown that the result has relatively good precision and completely satisfies the needs of projects.
引文
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