软粘土强度变化对防波堤稳定性影响分析

Analysis on influence of soft clay strength change to stability of breakwater

在地基软弱的离岸区域建造新港区,建筑物的失稳和破坏很大程度上与地基土体的承载能力有关。实际工程中,在软粘土地基上建造港工结构物大多会通过打设塑料排水板等对软土地基进行加固,如何科学的考虑软粘土地基抗剪强度的提升,最大限度的利用软粘土地基的承载能力,获得更为经济有效的工程设计施工方案,将是我国防波堤建设需要面对的重要研究课题之一。文章根据室内静三轴试验数据,研究不同荷载作用下软粘土强度变化规律,采用ABAQUS提供的接口对数值模型的土体材料属性进行二次开发,并结合实际工程,分析考虑软粘土强度变化后对沉箱式防波堤极限承载力的影响,计算结果表明:在竖向荷载作用下,由于软粘土抗剪强度的提升,防波堤安全系数提高了1.1,防波堤更加稳定安全;在水平波浪荷载作用下,结构的失稳主要受护肩和基床承载特性的影响,强度指标的提升对防波堤失稳影响较小。

The stability of port engineering building depends, to a great extent, on foundation bearing capacity,especially when the new port area is built in the offshore area of weak foundation. In practical engineering, peopleusually reinforce the soft soil foundation by setting the plastic drainage plate. How to consider the strength enhance-ment of soft clay foundation scientifically, make full use of the foundation bearing capacity of soft clay as far as pos-sible, will be one of the important research topics that we need to face in the construction of national breakwater.The paper carries out a series of researches on the strength change laws of soft clay under different loads throughstatic triaxial test, uses the interface of ABAQUS as second-development platform to put forward the numerical simu-lation method on strength change of soft clay, and analyzes the influence of the change for ultimate bearing capacityof caisson breakwater. The results show that： under the action of vertical load, the breakwater is more stable and thesafety factor of caisson breakwater is increased by 1.1 because of the enhancement of the soft clay shear strength.Under the action of horizontal load, the enhancement of the soft clay strength has little effect on the instability of thebreakwater which is mainly affected by the bearing characteristics of shoulder and bedding.