钢筋笼水泥土桩力学性能试验研究

发布时间：2018-04-29 11:31

本文选题：水泥土 + 钢筋笼水泥土桩　；参考：《中国地质大学(北京)》2014年硕士论文

【摘要】：近年来,在水泥土桩中加入型钢而成的钢筋水泥土桩做支护结构已经在世界范围内得到了广泛应用,而用钢筋笼取代型钢而形成的钢筋笼水泥土桩做支护结构还没有得到应用。针对钢筋笼水泥土桩的研究还处于室内研究阶段,对于水泥土中加入钢筋笼还没有实体桩的研究。本文旨在通过对水泥土桩的实体试验来研究钢筋笼水泥土桩在做支护结构时的受力情况。通过现场试验,分别研究钢筋笼水泥土桩在开挖过程、边坡堆载过程中的受力情况,并研究了地下水位上升、冠梁失去约束力和二次开挖的情况对钢筋笼水泥土桩的受力及其变化情况。在开挖过程中,坡顶背后土压力以及水泥土桩在开挖过程中会经历了复杂的应力变化过程；钢筋笼水泥土桩的截面最大弯矩出现在开挖面处;基坑开挖对水泥土桩开挖面以下受力影响范围为其开挖深度的0.9倍。钢筋笼水泥土桩做支护结构时,桩顶水平位移较大,因此,水泥土桩做支护结构时,开挖深度不宜过深,且应适当增加锚固构件。堆载对于水泥土桩的影响主要体现在堆载的初始阶段对桩身上部受力影响。地下水位上升不但影响桩身的受力情况,还能造成桩身强度变化,影响桩身受力的分布。在桩顶冠梁失去约束的情况下,桩身弯矩发生急剧变化,在基坑开挖面以上桩身受力变化最为明显。二次开挖对钢筋笼水泥土桩支护结构的影响主要体现在原基坑开挖面附近与基坑新开挖面附近桩身受力的变化,对桩身嵌固端和桩顶冠梁部位受力影响不大。
[Abstract]:In recent years, reinforced cement-soil pile used as support structure has been widely used in the world, but the reinforced caged cement soil pile which is formed by replacing steel bar with reinforced cage has not been applied. The research of reinforced cage cement soil pile is still in the research stage in laboratory, but there is no solid pile in cement soil. The purpose of this paper is to study the stress of reinforced caged cement soil pile when it is used as supporting structure through the solid test of cement soil pile. Through field test, the stress of reinforced caged cement soil pile during excavation and slope loading is studied, and the rise of groundwater level is studied. The stress and variation of reinforced caged cement-soil pile caused by the loss of binding force and second excavation of crown beam. During the excavation process, the earth pressure behind the slope top and the cement-soil pile will undergo a complex process of stress change during the excavation process, the maximum bending moment of the reinforced cage cement soil pile appears in the excavated surface. The influence of excavation on the excavation depth of cement soil pile is 0.9 times of its excavation depth. When reinforced cage cement soil pile is used as supporting structure, the horizontal displacement of pile top is larger. Therefore, when cement soil pile is used as supporting structure, the excavation depth should not be too deep, and anchoring member should be increased appropriately. The influence of surcharge on cement soil pile is mainly reflected in the initial stage of pile loading. The rise of groundwater level not only affects the stress of pile body, but also changes the strength of pile body and affects the distribution of pile body force. The bending moment of the pile body changes sharply when the crown beam of the top pile is out of constraint, and the stress change of the pile body above the excavation surface is the most obvious. The influence of secondary excavation on the support structure of reinforced cage cement soil pile is mainly reflected in the change of pile force near the excavation surface of the original foundation pit and near the new excavation surface of the foundation pit, but it has little effect on the stress of the embedded end of the pile body and the position of the crown and beam of the pile.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1

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