吹填造陆工程海堤抗滑稳定性研究与分析

发布时间：2018-06-02 04:17

本文选题：围海造陆 + 吹填　；参考：《天津大学》2014年硕士论文

【摘要】：近年来，随着经济建设的发展，城市综合用地需求急剧上升，围海造陆工程提出了向海洋要地的思路。利用船舶绞吸海里的泥沙吹填至海堤与陆地围成的区域，再通过地基处理的方法，，是目前传统的做法。然而前期的海堤工程在整个建设中起着至关重要的作用。由于新建海堤位于外海，在吹填成陆之前，海堤结构及地基面临着风浪、冲刷等外力的破坏，容易发生滑动破坏。因此在建设之前，海堤工程的安全稳定性是工程风险关键控制指标之一，也是设计人员重点关心的问题。本文结合某海堤工程具体实例，采用理论计算法和数值模拟法，对堤心充填管带外侧抛石式海堤结构整体抗滑稳定性进行计算分析，认为海堤工程管带老化导致充砂管带粘聚力下降对海堤工程整体抗滑稳定性有一定影响，主要体现在随着管带的老化，海堤工程的应力和位移均有不同程度的增大，其中水平位移变化最大；充砂管带粘聚力的下降导致海堤工程外侧护坡出现塑性变形区，说明管带的老化会导致外侧护坡滑坡进而引起海堤工程整体失稳。数值计算结果表明，冲淤基本平衡后海堤口门附近冲刷深度最大，两堤头的冲刷深度次之，且冲刷坑会延伸至堤跟附近，对海堤堤头的稳定性存在风险。在当前风浪条件下，当龙口滩面冲刷深度达15.5m时，海堤工程龙口堤头保护断面大块石护脚竖向位移较大，冲刷坡脚出现隆起，坡面出现明显的水平滑移，地基土层出现明显的滑动面，海堤工程堤头的整体存在失稳风险。文中针对海堤充填管带的老化和水下地形局部冲刷对海堤的整体抗滑稳定性进行了分析，指出在工程施工过程中的薄弱环节。其计算分析方法可对相似吹填造陆工程中的海堤抗滑稳定性研究提供参考和借鉴作用。
[Abstract]:In recent years, with the development of economic construction, the demand for urban comprehensive land has risen sharply. It is the traditional method to use the ship to carry the sediment from the sea to the area surrounded by the seawall and the land and then through the foundation treatment. However, the early seawall project plays an important role in the whole construction. Because the newly built seawall is located outside the sea, the structure and foundation of the seawall are subject to the damage of wind, wave, erosion and other external forces before it is filled into land. Therefore, before construction, the safety and stability of seawall project is one of the key control indexes of engineering risk, and it is also the key concern of designers. In this paper, a concrete example of a seawall project is used to calculate and analyze the overall anti-skid stability of the structure of riprap type seawall with the core filling pipe outside of the dike by using the theoretical calculation method and the numerical simulation method. It is considered that the decrease of the cohesive force of the sand filled pipe band caused by the aging of the pipe belt of the seawall works has a certain effect on the overall stability of the seawall project, which is mainly reflected in the increase of the stress and displacement of the seawall engineering in varying degrees with the aging of the pipe belt. The change of horizontal displacement is the biggest, and the decrease of cohesion of sand filled pipe zone leads to plastic deformation zone on the outside slope of seawall project, which indicates that the aging of pipe belt will lead to the landslide of lateral slope protection and then cause the overall instability of seawall project. The numerical results show that the depth of erosion near the entrance of the seawall is the largest after the basic balance of erosion and siltation, and the erosion depth of the two dikes is the second, and the scour pit will extend to the vicinity of the seawall, which is a risk to the stability of the head of the seawall. Under the current wind and wave conditions, when the erosion depth of Longkou beach reaches 15.5m, the vertical displacement of large block stone protecting foot of Longkou embankment head protection section, the uplift of scour slope foot and the obvious horizontal slip of slope surface appear. There is obvious sliding surface in the foundation soil, and the whole head of the seawall project is at risk of instability. In this paper, the overall anti-slide stability of seawall is analyzed according to the aging of seawall filled pipe belt and local erosion of underwater topography, and the weak links in the construction process are pointed out. The calculation and analysis method can be used as a reference for the study of anti-slide stability of seawall in similar reclamation engineering.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U656.314

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