防波堤地基的变形与稳定研究

发布时间：2018-02-01 12:45

本文关键词： 防波堤软土地基固结模拟稳定分析沉降　出处：《大连理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：防波堤是我国北方沿海地区常见的港口建筑物。修建在软土地基上的斜坡式防波堤,其施工期的安全稳定性尤为重要。在施工现场常常会遇到地基沉降不均匀,沉降速率过快的问题,此时如何确定地基在不断变形的情况下能否保持稳定是需要研究的问题。本文引入Biot固结理论,采用修正剑桥模型,借助大型非线性有限元软件ABAQUS研究了大连长兴岛葫芦山湾南防波堤工程中的地基沉降问题。通过对地基模型简化,模拟现场施工条件,求得了地基土体的沉降和水平位移,讨论了各个施工阶段的沉降特点及其影响因素,预测最终沉降量、工后沉降量和沉降引起的额外工程量。通过对比模拟,论证了应用塑料排水板处理地基的必要性。结合不同工况的沉降规律曲线,讨论了现有施工技术条件下工期安排的合理性。计算结果与实测值较为吻合。对于井群地基在2D模型中的简化方法的选取问题,通过算例的比较分析,在井群地基简化为“砂墙”地基和简化为均质地基这两种情况下,沉降计算结果的差异是微小的。根据固结模拟的计算结果,文中还应用边坡稳定分析方法中的极限平衡法,借助岩土工程软件GeoStudio对各施工阶段边坡的稳定性进行计算,重点讨论了施工期地基土体强度指标的选取,综合分析了斜坡式防波堤施工期的安全性。立足于施工单位和参建各方的角度,通过对斜坡式防波堤地基的固结变形分析和边坡稳定分析,得出：只有与施工实际相结合,综合分析沉降模拟结果、监测结果和安全系数才能有效的评价各施工阶段加载方式的合理性,找出需重点监测的施工阶段,得出正确的稳定性判断,对施工才会有一定的指导意义。
[Abstract]:Breakwater is a common port building in the northern coastal area of China. The safety and stability of slope breakwater built on soft soil foundation is very important. How to determine whether the foundation can maintain stability under the condition of continuous deformation is a problem to be studied. Biot consolidation theory is introduced and modified Cambridge model is adopted in this paper. The settlement of the foundation in the south breakwater of Hulu Bay, Changxing Island, Dalian is studied by means of the large-scale nonlinear finite element software ABAQUS. The field construction conditions are simulated by simplifying the foundation model. The settlement and horizontal displacement of foundation soil are obtained, the settlement characteristics and influencing factors of each construction stage are discussed, the final settlement, the settlement after construction and the extra engineering amount caused by settlement are predicted. The necessity of using plastic drainage board to treat foundation and the curve of settlement law under different working conditions are demonstrated. This paper discusses the rationality of the time limit arrangement under the existing construction technology. The calculated results are in good agreement with the measured values. For the selection of simplified method for well group foundation in 2D model, the comparison and analysis of calculation examples are made. When the well group foundation is simplified into a "sand wall" foundation and a homogeneous foundation is simplified, the difference in settlement calculation results is small. According to the calculation results of consolidation simulation, the limit equilibrium method of slope stability analysis method and geotechnical engineering software GeoStudio are used to calculate the slope stability in each construction stage. The selection of soil strength index for foundation during construction period is discussed, and the safety of slope breakwater during construction is analyzed synthetically. Based on the analysis of consolidation deformation and slope stability of slope breakwater foundation from the angle of the construction unit and the parties involved in the construction, it is concluded that only combined with the construction practice, the settlement simulation results can be comprehensively analyzed. Only the monitoring result and safety factor can effectively evaluate the rationality of the loading mode in each construction stage, find out the construction stage that needs to be monitored, and get the correct stability judgment, which will have certain guiding significance to the construction.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U656.2

【参考文献】