软土地基围堤外侧桩基础施工时机*

在软土地基上修筑港口工程时，外侧栈桥桩基础的施工时机和工程安全直接受到围堤填筑加载过程的制约和影响。依托某一级渔港工程，通过围堤加载过程中软土地基侧向变形分析及深层水平位移跟踪监测数据的多元回归拟合，分析预测了地基水平位移随围堤加载过程的变化规律和发展趋势，在此基础上通过ANSYS三维建模分析围堤加载过程中灌注桩的内力及变形，最终确定了外侧灌注桩基础的施工时机。研究表明：该软土地基在加载过程中的侧向变形符合指数函数变化规律；围堤加载而导致软土地基产生的侧向变形对外侧灌注桩位移的影响作用比对其自身内力影响要大；当地基土体上部产生最大水平位移150 mm时，灌注桩混凝土的屈服应力安全度仍较大，据此可提出外侧栈桥灌注桩基础的施工时机，该方法可供类似工程设计与施工借鉴。

Construction time of pile foundation outside embankment on soft soil

During construction of the port engineering on the soft soil foundation,the loading of embankment has enormous influence on the construction time and structural safety of the lateral pile foundation of the approach bridge.Based on a fishing port engineering,we study the lateral displacement of soft soil foundation of loading embankment and the regression of follow-up tracing data of deep horizontal,and forecast the change law and trend of development of later horizontal displacement of the foundation with the loading of embankment.According the ANSYS three-dimensional modeling,we analyze the internal force and deformation of bored piles with the loading of the embankment,and determine the construction time of lateral bored piles foundation.The research result shows that the lateral deformation of soft soil is consistent with the deformation law of index function in the process of load;under the action of lateral deformation of the soft soil foundation lateral deformation,the effect on the lateral displacement of the bored piles is bigger than its internal force influence;when the soft soil occurs 150 mm maximum horizontal displacement in the upper,the safety degree of yield stress of the surface concrete of bored pile is still larger,and accordingly we may know the construction time of the lateral bored piles foundation of approach bridge.This research may serve as reference for the design and construction of similar projects.