混凝土载体桩受力特性及设计方法研究
发布时间：2019-05-29 18:24
【摘要】：在普湾新区的建设过程中,工程中遇到了比较复杂的地质条件,在这种情况下,普通的预制桩和灌注桩达不到承载力的要求,根据这种情况,工程上采用了一种新型的桩,即载体桩。载体桩和一般的桩基存在着较大的不同,载体桩是一种典型的端承桩,主要靠桩端承受荷载,桩端所承受的荷载占整个桩所承受的荷载的80%以上,载体桩更不同于扩底桩,载体桩的施工过程中,在形成载体的过程中,加入一些高强度的碎石块等等,然后进行强夯,形成致密的结构,进而形成扩大的载体结果。它的受力机理和一般的桩基础存在着较大的差别。鉴于这种情况,本文展开了这项研究。从现场的试验中,得到了载体桩的Q-s曲线,并且对载体桩的极限承载力给出了值,根据Q-s曲线,可以为下文的ABAQUS数值模拟做出较好的校验。根据规范,对载体桩的极限承载力特征值进行计算,得出的值比现场试验的数值要小,这是合理的,因为规范所算出来的数据是保守的,再根据规范,得出同等条件下灌注桩的承载力,载体桩的极限承载力是灌注桩的3倍多,可见,载体桩使桩基础的承载力大大提高。除此之外,利用规范对载体桩的载体的直径进行估算,为下一章的模拟做好数据准备,最后对载体桩的最优桩距进行了研究,得出了合理的桩距,并且和工程的建筑施工图比较吻合。在Q-s曲线上,本文运用ABAQUS软件进行模拟,建立两个模型,即载体桩和普通的灌注桩,它们基于同等的条件下,地质条件相同,桩径的大小也一样,唯一的区别是载体桩有载体这一部分。通过模拟,分别得到两种不同的沉降曲线,根据现场试验和其他的大量的试验,发现载体桩的Q-s曲线是缓变型。在受力机理上,载体桩的受力情况和普通的灌注桩存在着较大的差别,在载体桩载体的周围土体上,应力呈现出比较均匀的分布,普通灌注桩周边存在着应力集中的现象,这一点使整个受力体系存在着较大的差别。最后,本文对载体桩的Q-s曲线进行了曲线拟合,得出公式：y=1-e-Ax A∈(-0.00133,0.00108),可以作为简单的公式用于现场的设计和施工。
[Abstract]:In the process of construction of Puwan New area, complex geological conditions have been encountered in the project. In this case, ordinary precast pile and cast-in-place pile can not meet the requirements of bearing capacity. According to this situation, a new type of pile is adopted in the project. That is, the carrier pile. There is a great difference between the carrier pile and the general pile foundation. The carrier pile is a typical end-bearing pile, which mainly depends on the load at the end of the pile. The load on the pile end accounts for more than 80% of the load borne by the whole pile, and the carrier pile is different from the extended pile. In the construction process of the load pile, in the process of forming the carrier, some high strength broken stones and so on are added, and then the dynamic compaction is carried out to form the dense structure, and then the expanded carrier result is formed. There is a great difference between its stress mechanism and the general pile foundation. In view of this situation, this paper carries out this study. From the field test, the Q 鈮，
本文编号：2488126
[Abstract]:In the process of construction of Puwan New area, complex geological conditions have been encountered in the project. In this case, ordinary precast pile and cast-in-place pile can not meet the requirements of bearing capacity. According to this situation, a new type of pile is adopted in the project. That is, the carrier pile. There is a great difference between the carrier pile and the general pile foundation. The carrier pile is a typical end-bearing pile, which mainly depends on the load at the end of the pile. The load on the pile end accounts for more than 80% of the load borne by the whole pile, and the carrier pile is different from the extended pile. In the construction process of the load pile, in the process of forming the carrier, some high strength broken stones and so on are added, and then the dynamic compaction is carried out to form the dense structure, and then the expanded carrier result is formed. There is a great difference between its stress mechanism and the general pile foundation. In view of this situation, this paper carries out this study. From the field test, the Q 鈮，
本文编号：2488126
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