抗滑桩桩间拱效应与桩板土压力研究

发布时间：2018-01-24 17:30

本文关键词： 抗滑桩拱效应桩板墙土压力双排桩模型试验排间距　出处：《重庆大学》2014年博士论文　论文类型：学位论文

【摘要】：由于抗滑桩具有圬工小，抗滑能力大，支挡效果好等优点，目前在铁路、公路、水电、市政和矿业等岩土工程领域广泛采用。随着抗滑桩大量使用，其设计计算等方面得到了较大的发展。然而由于岩土性质的复杂性，抗滑桩在成拱机理、挡板土压力计算以及大型滑坡双排桩支挡效果等方面尚未达成共识。为此，论文以国家自然科学基金“悬臂式抗滑桩三维土拱效应研究”（编号：50878218）和国家“十二五”科技计划支撑课题（编号：2012BAJ22B06）“村镇区域空间规划与土地利用优化技术集成示范”为依托，在土体成拱效应分析的基础上，对桩板土压力的分布规律，双排桩的传力机制进行了深入研究。主要研究工作如下：（1）在土体成拱效应分析的基础上，将抗滑桩支挡反力看成作用在半平面边界上的分布力，，然后利用弹性理论对桩后土体中的附加应力进行了计算，揭示了桩间拱效应的形成机理。在此基础上建立了抗滑桩合理桩间距与拱轴线计算模型与计算公式，并分析了桩间岩拱存在的可能性，同时建立了岩拱的计算模型与计算方法。（2）结合前述桩间土拱的形成机理，在室外设计了大型推力试验。试验分桩前挂板与桩后做板两种方案进行，分别对两方案桩间土拱效应与桩板土压力的变化规律进行了深入研究。在此基础上建立了桩间挡板土压力计算模型,推导了桩间挡板土压力定量计算公式。并与实测结果、规范法（筒仓法）以及传统的卸荷拱法进行了对比。（3）限于室外大型试验装置局限性，文中设计了室内模型推桩试验，全面系统地对抗滑桩桩间土拱效应与传力机制进行了研究。在室外大型试验的基础上，结合悬臂桩在大于计算合理桩间距条件下桩间土拱效应与推力荷载传递试验，以及埋入式抗滑桩桩后与桩前土拱效应研究，对双排桩不同排间距条件下桩间、排间土拱效应与双排桩的传力规律进行了研究。（4）在室内模型试验基础上，文中对双排桩的传力机制进行了深入分析，并提出了双排桩合理排间距的确定原则，同时基于Janbu分析法和弹性地基理论建立了双排桩各排桩推力及抗滑阻力方程组，提出了利用全段法和分段迭代法分析桩身变位及内力计算公式；最后基于模糊评判理论，以稳定安全系数、各桩排推力和以及两排桩的推力差为目标函数，提出了双排桩优化设计方法。（5）在桩间土拱效应与桩板土压力研究基础上，进一步利用室外大型试验与室内模型试验，对作用于桩板上的土压力进行了长时间观测，对桩间土拱的蠕变效应与桩板土压力的时间效应进行了深入研究。
[Abstract]:As anti-slide piles have the advantages of small masonry, large anti-slide ability, good retaining effect and so on, they are widely used in geotechnical engineering fields such as railway, highway, hydropower, municipal and mining, etc. With the extensive use of anti-slide piles. However, due to the complexity of geotechnical properties, anti-slide pile in the arch mechanism. There is no consensus on the calculation of retaining plate earth pressure and the retaining effect of large landslide double-row piles. In this paper, the National Natural Science Foundation of China "Research on the Three-Dimensional soil Arch effect of cantilever Anti-slide pile" (No.: 50878218) and the "12th Five-Year Plan" supported by the National Science and Technology Plan (. Number: 2012BAJ22B06. "Integrated demonstration of Regional Spatial Planning and Land use Optimization in villages and towns". Based on the analysis of soil arch effect, the distribution law of soil pressure of pile plate and the transmission mechanism of double row pile are deeply studied. The main research work is as follows: 1) based on the analysis of soil arch effect, the anti-slide pile retaining reaction force is regarded as the distributed force acting on the half-plane boundary, and then the additional stress in the soil behind the pile is calculated by using the elastic theory. The forming mechanism of the arch effect between piles is revealed, and the calculation model and formula of reasonable pile spacing and arch axis of anti-slide pile are established, and the possibility of rock arch between piles is analyzed. At the same time, the calculation model and method of rock arch are established. 2) combined with the formation mechanism of the soil arch between piles, a large thrust test was designed outdoors. The test was carried out by two schemes: the front hanging plate of pile and the plate behind pile. The soil arch effect between piles and the variation of soil pressure between piles and plates are studied, and the calculation model of soil pressure between piles is established. The formula for calculating the earth pressure between piles is derived and compared with the measured results, the canonical method (silos method) and the traditional unloading arch method. In order to limit the limitation of outdoor large-scale test equipment, this paper designs an indoor model pushing test, and studies the mechanism of soil arch effect and force transfer between sliding piles in a comprehensive and systematic way. On the basis of outdoor large scale test, the paper studies the effect of soil arch and the mechanism of force transfer between sliding piles. Combined with soil arch effect and thrust load transfer test of cantilever pile under the condition of calculating reasonable pile spacing, and soil arch effect after embedded anti-slide pile and soil arch effect in front of pile, the soil arch effect between piles under different row spacing of double-row piles is studied. The effect of soil arch between rows and the force transfer law of double row piles are studied. 4) on the basis of indoor model test, this paper makes a thorough analysis on the mechanism of force transfer of double-row piles, and puts forward the principle of determining reasonable row spacing of double-row piles. At the same time, based on Janbu analysis method and elastic foundation theory, the equations of thrust and anti-slide resistance of each row pile of double-row pile are established, and the formulas for calculating the displacement and internal force of pile body are put forward by using full-section method and piecewise iteration method. Finally, based on the fuzzy evaluation theory, the optimal design method of double-row piles is put forward with the objective function of the stable safety factor, the thrust of each pile row and the thrust difference between the two rows of piles. 5) based on the research of soil arch effect between piles and soil pressure of pile plate, the soil pressure acting on pile plate is observed for a long time by using outdoor large-scale test and indoor model test. The creep effect of soil arch between piles and the time effect of soil pressure on pile plate are studied.
【学位授予单位】：重庆大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU473.1;TU432

【参考文献】