基于桩身内力测试值和压缩量的桩端荷载计算
|
摘要
振弦式钢筋应力计法是一种常用的桩身内力测试方法,按照测试要求,钢筋计埋设位置与桩底的距离一般为1.5~3.0倍桩径,采用钢筋计无法直接测出桩端荷载;而桩底压力盒因桩底非平面、受力不均匀等原因难以获得有效的测试数据,多数情况下仅能得到桩端持力层的总阻力,使得桩端持力层的端阻力和侧阻力获取具有经验性。提出了一种利用桩身内力测试数据和桩身压缩量计算桩端荷载的方法,该方法利用桩身内力、桩身压缩量以及桩身受力与变形的关系计算出桩端荷载,利用桩端荷载计算出桩端持力层的端阻力和侧阻力参数。工程实例表明,该方法切实可行,是对钢筋计法测量桩身内力的补充完善,提高了试桩成果的可靠性,具有很好的应用价值。
Vibrating wire type steel bar stress gauge is commonly used in pile test. Since the gauge is buried at the height of 1.5 ~ 3 times pile diameter above the pile bottom,the pile-end load can't be obtained directly. Also it's difficult to obtain valid test data by the pressure cells that is unevenly compressed due to non-planar surface of pile bottom. So the engineering experiences have to be used in figuring out the end and skin resistance of the pile-end bearing stratum. We propose a method that can calculate the pile-end load by the measured axial force and compression deformation of pile body. The method can be used to calculate the pile-end load by the pile axial force,compression deformation and the relationship between stress and deformation of pile body,then the end and skin resistance of the pile-end bearing stratum is calculated by the pile-end load. An actual project example demonstrates that the method is feasible and complements the reinforcement stress gauge method and increases the reliability of pile testing results.
Vibrating wire type steel bar stress gauge is commonly used in pile test. Since the gauge is buried at the height of 1.5 ~ 3 times pile diameter above the pile bottom,the pile-end load can't be obtained directly. Also it's difficult to obtain valid test data by the pressure cells that is unevenly compressed due to non-planar surface of pile bottom. So the engineering experiences have to be used in figuring out the end and skin resistance of the pile-end bearing stratum. We propose a method that can calculate the pile-end load by the measured axial force and compression deformation of pile body. The method can be used to calculate the pile-end load by the pile axial force,compression deformation and the relationship between stress and deformation of pile body,then the end and skin resistance of the pile-end bearing stratum is calculated by the pile-end load. An actual project example demonstrates that the method is feasible and complements the reinforcement stress gauge method and increases the reliability of pile testing results.
引文
[1]李锋.钢筋应力计在桩身轴力测试中的计算方法[J].浙江水利水电学院学报,2015,27(2):62-65.
[2]屈希峰,陈海桦.静载试验与钢筋计测试联合确定桩基承载力[J].四川建筑,2008,28(1):162-163.
[3]中华人民共和国住房和城乡建设部.建筑基桩检测技术规范JGJ106-2014[S].北京:中国建筑工业出版社.
[4]郅正华,李汇丽,王亮.桩身压缩量的计算原理及工程应用[J].岩土工程界,2008,11(4):58-59.
[5]胡建强.钻孔灌注桩桩周土阻力的测试与分析[J].工程勘察,2009,(S2):381-387.
[6]申鲁,张文峰,李钊,等.南水北调中线沙河梁式渡槽桩基承载力测试[J].人民长江,2013,44(16):77-81.
[7]郅正华.利用桩身压缩量计算单桩承载力的辅助分析[J].工程勘察,2008(S2):128-130.
[8]陈竹昌,宋荣.单桩桩身压缩量的分析计算[J].中国公路学报,1992,5(1):69-75.
[9]任光勇,张忠苗,宋仁乾.桩身混凝土在竖向荷载作用下的压缩量试验研究[J].岩石力学与工程学报,2004,23(2):348-354.
[10]张忠苗.软土地基超长嵌岩桩的受力性状[J].岩土工程学报,2001,23(5):552-556.
[11]颜钟,李端有,李强.三向位移计在桩基测试中的应用[J].人民长江,2011,42(24):41-44.
[2]屈希峰,陈海桦.静载试验与钢筋计测试联合确定桩基承载力[J].四川建筑,2008,28(1):162-163.
[3]中华人民共和国住房和城乡建设部.建筑基桩检测技术规范JGJ106-2014[S].北京:中国建筑工业出版社.
[4]郅正华,李汇丽,王亮.桩身压缩量的计算原理及工程应用[J].岩土工程界,2008,11(4):58-59.
[5]胡建强.钻孔灌注桩桩周土阻力的测试与分析[J].工程勘察,2009,(S2):381-387.
[6]申鲁,张文峰,李钊,等.南水北调中线沙河梁式渡槽桩基承载力测试[J].人民长江,2013,44(16):77-81.
[7]郅正华.利用桩身压缩量计算单桩承载力的辅助分析[J].工程勘察,2008(S2):128-130.
[8]陈竹昌,宋荣.单桩桩身压缩量的分析计算[J].中国公路学报,1992,5(1):69-75.
[9]任光勇,张忠苗,宋仁乾.桩身混凝土在竖向荷载作用下的压缩量试验研究[J].岩石力学与工程学报,2004,23(2):348-354.
[10]张忠苗.软土地基超长嵌岩桩的受力性状[J].岩土工程学报,2001,23(5):552-556.
[11]颜钟,李端有,李强.三向位移计在桩基测试中的应用[J].人民长江,2011,42(24):41-44.