高桩码头对邻近爆破的非线性动力响应分析
Nonlinear dynamic response analysis of blasting to adjacent high-pile wharf
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摘要: 爆破施工会对周围已有的建筑物产生安全隐患, 因此, 预测爆破施工对周边建筑物的影响能有效降低风险, 消除安全隐患。在某港口周边进行爆破施工前, 为保证邻近高桩码头的安全, 先建立爆破位置与高桩码头整个区域的三维非线性有限元数值模型。在爆破荷载及高桩码头在役期间的最不利荷载作用下, 计算分析港口内部结构与土的非线性相互作用动力响应。根据港口结构所能承受的爆破冲击波通过土体传递给结构的动力响应, 并以高桩码头的安全振动速度为衡量标准, 得到爆破点距离码头最近位置时的最大单孔炸药量, 分析此时码头的位移变形、弯矩、剪力以及应变情况, 发现码头的位移受爆破荷载的影响较小, 但码头内部斜桩较直桩承受更大的应力、剪力, 因此在爆破施工时, 斜桩更容易受到破坏。Abstract: The blasting construction may cause potential risk to adjacent buildings. In order to reduce the risk effectively or even eliminate it, the accurate prediction of the influence of blasting construction is of much importance. Therefore, to ensure the stability of an adjacent pile wharf, a three dimensional nonlinear finite element model for the whole area of the blasting location and the high-pile wharf is established before the blasting construction around the wharf. Afterwards, under the effect of the blast loading and the most unfavorable load of high-piled wharf during service, the dynamic response of the nonlinear interaction between the internal structure of the harbor and the soil is calculated and analyzed. In line with the dynamic response which caused by the shock wave and delivered through soil that the wharf structure can withstand, and taking safety vibration velocity of the high pile wharf as the measuring standard, the biggest dosage of the single blast hole closest to the wharf is obtained. In the mean time, the displacement, bending moment, shear force and strain of the wharf are analyzed. According to the result, the displacement of the wharf under blasting load is of little influence, while the inclined piles inside the wharf bear more stress and shear force than the vertical piles. In conclusion, inclined piles are more vulnerable in the blasting construction.