Countermeasures for enhancing the stability of composite breakwater under earthquake and subsequent tsunami
Countermeasures for enhancing the stability of composite breakwater under earthquake and subsequent tsunami
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DOI：
10.1007/s11440-017-0615-4
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发表时间：
2018-08
期刊：
影响因子：
5.7
通讯作者：
B. Chaudhary;H. Hazarika;A. Murakami;K. Fujisawa
中科院分区：
文献类型：
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作者：
B. Chaudhary;H. Hazarika;A. Murakami;K. Fujisawa
过去，许多防波堤由于地震和随后的海啸而倒塌，造成相当大的破坏，因为防波堤未能阻止海啸进入沿海平原地区。防波堤的破坏主要是地基破坏造成的。然而，防波堤基础在地震和海啸作用下的破坏机理尚不清楚。本研究主要探讨在地震及海啸作用下，防波堤因地基崩塌而破坏之机制。提出了减轻地震海啸复合地质灾害破坏的防波堤基础加固对策。采用板桩和石笼加固防波堤地基。为了评价加固地基的效果，进行了一系列的振动台试验和水工模型试验。在地震荷载作用后，对同一模型进行了海啸溢流试验，并对常规基础和加筋基础进行了比较。试验结果表明，加筋地基能有效地减小防波堤在地震和海啸作用下的破坏。通过数值分析，阐明了土-防波堤-水泥-流体系统的作用机理。研究结果对实际工程具有一定的参考价值，为今后海洋结构物的抗震加固提供了参考。
Many breakwaters have collapsed in the past due to earthquakes and subsequent tsunamis, resulting in considerable devastation as the breakwaters failed to prevent the tsunami from entering the coastal plain areas. Breakwater failures are mainly caused by damage to its foundation ground. However, the damage mechanism of breakwater foundation during earthquakes and tsunamis remains unclear. This study focuses on the breakwater failure mechanism due to collapse of its foundation under the action of an earthquake and subsequent tsunami. In addition, reinforcing countermeasures for breakwater foundation to mitigate damage due to compound geodisasters triggered by earthquakes and tsunamis are proposed. Sheet piles and gabions were used in the breakwater foundation as reinforcing countermeasures. To evaluate the effectiveness of the reinforced foundation, a series of shaking table tests and hydraulic model tests were performed. The tsunami overflow tests were conducted on the same model after the earthquake loadings, and comparisons were made between the conventional and reinforced foundations. It was observed during the tests that the reinforced foundation could effectively reduce the damage to the breakwater caused by earthquake and tsunami-induced forces. Numerical analyses were performed to clarify the mechanism of the soil–breakwater–reinforcement–fluid system. Overall, this study is useful in practical engineering, and the reinforcing foundation model could be adopted for offshore structures to reduce damage from earthquakes and tsunamis in the future.