桩论文桩承载力自平衡测试技术研究与探讨.doc

桩论文：桩承载力自平衡测试技术研究与探讨【中文摘要】自平衡测试法是一种新的确定单桩承载力的方法,相对于传统的静载荷试验,具有很大的优势。它解决了大吨位桩、水上桩、斜桩等做单桩承载力的困难,而且能够节约成本,试验装置简单,不需要提供大量的堆载用的物料等。本文首先介绍了桩基技术的现状与发展趋势,指出目前桩基技术正朝着大承载力的方向发展,新理论不断涌现,新型施工技术也在发展。由于基桩是隐蔽工程,所以检测是很有必要的,在本文中对几种检测方法进行了简要对比：在基桩完整性检测方面主要的方法有低应变反射波法、声波透射法等,在承载力检测方面主要是高应变法和静载试验。自平衡法是目前新兴的检测承载力的方法,本文对该法在国内外的发展情况作了简要介绍,指出了与传统静载试验相比的优点。重点归纳介绍了自平衡测试技术的原理、试验步骤、承载力的确定等,并对常用的三种自平衡测试技术进行了对比,指出通莫试桩法在可靠性和准确性上要占优势。本文重点分析了竖向承载桩的荷载传递机理及其影响因素,然后分析了自平衡试桩法的荷载传递机理,并在桩周土应力状态、桩身受力情况、桩端破坏形式以及正负摩阻力方面深刻阐述了自平衡测试法与传统静载压桩的荷载传递机理的区别。归纳总结了影响自平衡测试法荷载传递的因素主要有以下三个方面：桩与土之间的刚度比、桩侧下层土与上层土刚度比、桩端土与桩周土刚度比。荷载箱位置的放置问题,也就是平衡点的寻找问题,是影响自平衡试验能否准确可靠完成的关键性工作。本文对总结了国内现在已经开始应用的工程实例中的荷载箱放置情况。分析了确定平衡点位置的方法,主要有经验值法、相似模拟试验法和数值模拟试验法,最常用的经验值法能够满足工程实际的需要。自平衡法试验参数以及位移-荷载曲线如何向传统静载压桩转换的问题也是试验的关键工作,其方法主要有经验转换法和精确转换法。其中经验转换法是目前较常用的方法,也是比较简单直接的方法,其精度能够满足工程实际的需要。精确转换法理论水平较高,试验参数的精确度也高,一般应用于大型工程当中,在国内不是很普及。最后,结合二环东路工程实践,对自平衡测试法的应用做了介绍,指出在测试大承载力桩方面,自平衡法的适用性和可靠性。【英文摘要】Self-balanced test method is a new method to determine the bearing capacity of the single pile, Compared with the traditional static loading test,It has a big advantage. It has solved the difficulty of single pile bearing capacity of pile,but also can save cost, test simple device, etc.This paper firstly introduces the status and development of pile foundation technology trends and then points out, the bearing capacity of pile foundation technology is headed in the direction of big emerging new theory, new construction technology is also in development.In this paper several detection method in brief areexpounded comparison:in the inspection of the main method has low strain reflected wave method, ultrasonic transmission method and so on, in the inspection of the bearing capacity is mainly static load test and high stress dynamic.Self-balanced method is currently emerging detection capacity method, this paper briefly introduced the development of both at home and abroad and, points out the different with traditional static load test of advantages.The article analyses the vertical bearing the load-transferring mechanism and the influencing factors, and then analyzes the pile trialing self balanced load transfer mechanism, and in a pile soil stress state and pile body stress and pile end destroying forms and positive and negative friction aspects elaborated profoundly from balance test method with traditional static load pressure pile load transfer mechanism of differentiation.The placement position of load cases, also mean searching questions of equilibria, which affect the balance test of whether complete critical work accurately and reliably. This paper summarizes the domestic that is now starting to engineering application and the load box placed situation examples. Analyzes the method of equilibrium position determined, mainly has experience value method, analog simulation test method and numerical simulation experiment method, the most commonly used experience value method can satisfy the demand of practical engineering. Self-balanced test parameters and how displacement load curve to the traditional static load piling conversion problem is the key work, the experiment method to basically have experience conversion method and precise conversion method. The experience conversion method is a commonly used method, also be more direct and simple method, its precision can satisfy engineering practical needs. Accurately change law theory level to be higher, the accuracy of the test parameters is high also, generally applied to large of the project is not very popular in domestic.Finally, combined with engineering practice, erhuanxi road of the application of balance testing method is introduced, points out that in the test, large capacity since balance method of pile the applicability and reliability.【关键词】桩 自平衡 承载力 平衡点【英文关键词】pile self-balanced method bearing capacity balance point【目录】桩承载力自平衡测试技术研究与探讨中文摘要7-8ABSTRACT8-9符号说明10-12第一章 绪论12-241.1 桩基技术的现状与发展趋势12-131.2 基桩检测技术的现状13-191.2.1 动力检测技术14-151.2.2 声波透射法检测15-161.2.3 钻芯法检测16-171.2.4 静载荷试验17-181.2.5 几种检测方法的对比18-191.3 自平衡测试技术19-221.3.1 自平衡测试技术在国外的发展201.3.2 自平衡测试技术在国内的发展20-211.3.3 测试方法介绍21-221.3.4 自平衡测试技术的优点221.4 问题的提出22-24第二章 自平衡测试法24-312.1 测试原理24-252.2 试验装置25-262.3 试验时间及加载方式26-272.4 试验步骤27-282.5 终止加载条件282.6 承载力的确定28-292.7 几种常用的自平衡方法的比较29-302.8 本章小结30-31第三章 桩体荷载传递机理分析31-453.1 竖向承载桩基的工作原理313.2 桩土荷载传递分析31-333.3 桩侧阻力分析33-363.4 桩端阻力分析36-383.5 自平衡试桩法的荷载传递机理38-403.6 自平衡法与传统静载压桩荷载传递机理的区别40-423.7 自平衡试桩法荷载传递的影响因素42-443.8 本章小结44-45第四章 荷载箱位置的确定及试验参数的等效转换方法45-554.1 荷载箱位置归纳45-474.2 荷载箱位置影响分析474.3 确定平衡点位置的方法47-494.3.1 经验值法47-484.3.2 相似模拟试验法48-494.3.3 数值模拟试验法494.4 试验参数的等效转换方法49-544.4.1 经验转换法49-514.4.2 精确转换法51-534.4.3 两种转换方法的比较53-544.5 本章小结54-55第五章 自平衡测试法工程应用55-675.1 工程概况555.2 试验目的555.3 试桩主要技术资料55-565.4 试验原理565.5 试验装置56-585.5.1 试验原