摘要:
如何将抗滑结构折算为二维模型，是二维离散元模拟边坡加固计算的首要问题。针对抗滑桩，根据“弹性桩”的位移和内力计算公式，通过推导变换，得出桩身位移xy、转角 与EI呈负相关，与桩身受力大小正相关；桩身任意点处的弯矩和剪力与EI无关，只与桩身受力大小正相关。该规律在“刚性桩”条件下进行推理同样成立。利用这一规律，将间距为d的抗滑桩EI折算为实际的1/d，进行二维计算，能得到与实际相同的桩身位移和转角；二维计算的桩身应力值乘以d，得到实际的桩身应力值。对EI折算的不同折算组合进行模拟验证，结果表明，E或I各单独折算或EI均进行折算，能得到相同的桩身应力和变形。最后，对张石高速公路类土质边坡抗滑桩进行实例计算，折算后的抗滑桩能够计算出与实际规律相符的桩身应力和应变。
Abstract:
For 2D slope reinforcement DEM simulation, the first consideration is the conversion of anti-sliding structure into a 2D model. There are two mechanical models and corresponding calculation methods of embedding section of anti-sliding piles, which are classified into rigid pile model and elastic pile model according to the relative rigidity of pile-soil system. Laws governing the elastic anti-sliding pile model are brought forward from formula deduction. First, the strain of the pile is in inverse proportion to its EI and in positive correlation to the force acting on it. Second, the stress of the pile is independent of EI and in positive correlation to the force acting on it. The two rules are also correct for the rigid anti-sliding model. Under these rules, considering a line of piles with a distance of d in a 2D simulation model of unitage of thickness, the force acting on the pile is only 1/d of the actual value, considering EI of the pile to be converted to its 1/d, then the realistic strain can be yielded through simulation, and the stress obtained is 1/d of the actual value, which is only in positive correlation to the force. Four different transformation examples of EI are calculated. Results show that the same strain and stress can be obtained under the four situations, no matter we just change E to E/d, or just I to I/d, or both E and I of the pile to make its EI become 1/d of the actual value. A similar soil slope project of Zhangjiakou-Shijiazhuang Expressway is simulated using this method, and the strain and stress of anti-sliding piles are agreed with the actual rules.
百度学术
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