基桩自平衡法静载试验分析及荷载箱的改良和应用

发布时间：2018-03-15 11:34

本文选题：基桩　切入点：检测　出处：《山东大学》2016年硕士论文　论文类型：学位论文

【摘要】：自平衡法静载试验是一种新型的基桩承载力测试方法,其充分利用桩的摩擦力与端阻力作为一对平衡力的基本原理,在大吨位超长桩的承载力检测时基本不受承载力和场地条件的限制,同时,能够提供多方面的试验数据,拓展了基桩静载试验的应用范围、降低了试验成本、提高了试验过程安全度。本文简要的阐述了分析和研究自平衡法静载试验及其试验加载设备荷载箱的意义,国内外的发展现状：叙述分析了基桩不同试验方法的荷载传递机理,自平衡法静载试验的基本原理,各种等效转换方法,平衡点的确定和荷载箱的埋设等；重点在于自平衡法静载试验设备荷载箱的改良研究和实际工程应用。荷载箱是进行自平衡法静载试验的关键核心设备,其设计和产品质量直接影响自平衡法静载试验的检测结果。由于传统荷载箱上、下面处容易滞留浮浆等不良介质造成该部位桩身混凝土质量不均,加载时,导致荷载箱上、下面处应力应变复杂,变形不均,进而导致安装于荷载箱上下面处的位移观测装置测量到的观测值与桩身实际的应力应变值严重不符,且荷载箱部位容易侵入杂质,影响后期注浆加固效果,同时,传统荷载箱存在现场安装程序复杂,加固困难等问题。为克服传统荷载箱的上述技术缺陷,提高荷载箱的质量和性能,本文对于荷载箱的改良,重点研究内容为：低油压高出力顶、特殊设计筒式结构、位移装置、观测点的位置布置、荷载箱部位声测管的连接、试验后高压注浆等方面的研究。并且,通过工程实例,将改良设计和生产的荷载箱-基桩轴向自反力测试筒式荷载箱与传统荷载箱在同条件下进行试验比对,验证其设计目的和产品质量性能。经工程试桩检验验证,本文所述基桩轴向自反力测试筒式荷载箱在同等条件下具有低油压高出力、试验荷载维持正常、位移观测点布置合理、试验测试数据准确、声测管连接合理和试验后注浆加固效果显著等优势。同时,基桩轴向自反力测试筒式荷载箱,获得了实用新型专利证书,证书号：ZL201420192943.4；目前,该荷载箱已在多个工程项目中推广使用,均圆满的完成了试验任务。最后,总结论证自平衡法静载试验检测数据和分析结果,指出基桩轴向自反力测试筒式荷载箱的设计合理、质量可靠,将随着自平衡检测技术法发展,逐渐被认可和推广应用。
[Abstract]:Self-balance static load test is a new method for testing the bearing capacity of pile, which makes full use of friction force and end resistance of pile as the basic principle of a pair of equilibrium forces. The bearing capacity of super-long pile with large tonnage is not limited by bearing capacity and site condition. At the same time, it can provide a variety of test data, expand the application scope of pile static load test, and reduce the test cost. In this paper, the significance of analyzing and studying the static load test of self-balancing method and the load box of the test equipment is briefly described. The development situation at home and abroad is described. The load transfer mechanism of different test methods of foundation pile is described and analyzed. The basic principle of static load test by self-balance method, various equivalent conversion methods, the determination of equilibrium point and the installation of load box, etc. The emphasis is on the improvement research and practical engineering application of load box, which is the key equipment for self-balancing static load test. Its design and product quality directly affect the test results of static load test by self-balancing method. Because of the poor media such as floating slurry and other bad media in the traditional load box, the quality of pile body concrete in this part of the pile is uneven, and when loading, it leads to the loading box. The stress and strain at the bottom of the pile are complicated and the deformation is uneven, which leads to the measurement of displacement at the bottom of the load box that is seriously inconsistent with the actual stress and strain value of the pile body, and the load box is prone to intrude into the impurity. In order to overcome the technical defects of the traditional load box and improve the quality and performance of the load box, the improvement of the load box is made in this paper, in order to overcome the technical defects of the traditional load box and improve the quality and performance of the load box, in order to overcome the technical defects of the traditional load box, improve the quality and performance of the load box, The main research contents are as follows: low oil pressure and high output roof, specially designed cylinder structure, displacement device, location arrangement of observation point, connection of acoustic tube in load box, high pressure grouting after test and so on. This paper compares the improved design and production of the load box with the traditional load box under the same conditions, and verifies the design purpose and the quality performance of the product, which is verified by the engineering pile test. The axial self-reflexive force of the pile in this paper has low oil pressure and high output force under the same conditions, the test load remains normal, the displacement observation points are arranged reasonably, and the test data are accurate. At the same time, the pile axial self-reflexive force test bobbin load box, obtained the utility model patent certificate, certificate no.: ZL201420192943.43.4; at present, the foundation pile axial self-reaction test cylinder load box has obtained the utility model patent certificate, the certificate number: ZL201420192943.43.4. The load box has been widely used in many engineering projects and has successfully completed the test task. Finally, the test data and analysis results of static load test by self-balance method are summarized and demonstrated. It is pointed out that the design of the pile axial self-reaction test cylindrical load box is reasonable. With the development of self-balanced detection technology, quality and reliability will be accepted and popularized.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU473.16

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