自重、渗流及地震耦合作用下人工岛动力稳定性分析

发布时间：2018-07-21 12:07

【摘要】：针对人工岛在自重、渗流、地震等耦合作用下动力稳定性研究较少的现状,以某人工岛边坡为例,首次将强度折减动力分析法引入到人工岛动力稳定性分析中,建立有限元数值分析模型,采用Finn-Byrne和修正Hardin-Drnevich动力本构,对多场耦合作用下人工岛液化范围、受力情况及动力稳定性进行分析。计算表明:1在设防烈度地震作用下,人工岛能够满足动力稳定性要求,由于海底淤泥层抗剪强度很低,地震下的最终破裂面由抛填块石下部与淤泥层共同组成;2岛内侧降水,使得海水渗流方向由岛外指向岛内,增加岛外侧土体有效应力,提高其抗液化能力,降低了岛内土体的有效应力,因此地震作用下内侧土体更易液化;3由于受到周围土体的约束作用,土体局部液化不会产生液化大变形,只有液化土体较多才会产生大变形。研究结果为人工岛动力分析提供参考。
[Abstract]:In view of the fact that the dynamic stability of artificial island is less studied under the coupling of gravity, seepage and earthquake, the strength reduction dynamic analysis method is introduced into the dynamic stability analysis of artificial island for the first time, taking an artificial island slope as an example. Finn-Byrne and modified Hardin-Drnevich dynamic constitutive model were used to analyze the range, force and dynamic stability of artificial island liquefaction under multi-field coupling. The calculation results show that the artificial island can meet the requirement of dynamic stability under the action of earthquake intensity. Due to the low shear strength of the silt layer, the final fracture surface under the earthquake is composed of the lower part of the rockfill and the silt layer to make up the precipitation of the inner part of the island. The seepage direction of seawater is pointed to the island from the outside of the island, which increases the effective stress of the soil outside the island, improves its anti-liquefaction ability, and reduces the effective stress of the soil in the island. Therefore, it is easier for the medial soil to liquefy under the earthquake, because it is restricted by the surrounding soil, the local liquefaction of the soil will not produce large liquefaction deformation, but only more liquefaction soil will produce the large deformation. The results provide reference for dynamic analysis of artificial islands.
【作者单位】：后勤工程学院军事土木工程系;岩土力学与地质环境保护重庆市重点试验室;重庆市地质灾害防治工程技术研究中心;重庆交通大学土木工程学院;
【基金】：国家重点研究发展计划(973)项目(2011CB013600) 国家自然科学基金(51378496;51178457;41272285) 重庆自然科学基金(CSTC2013JCYJYS0002)
【分类号】：P756.8

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