摘要
通平高速公路是湖南省规划的"五纵七横"高速公路网中第一纵(平汝高速公路)中的第一段。为探求通平高速公路上坪汨罗江特大桥基桩的竖向承载机理,选取k56+295处的上坪汨罗江特大桥22#墩中的一根工程桩为试验桩,通过试验设计、测试设备的埋设以及加载与测试,开展了现场静载试验,得到该试验桩的桩顶Q—s曲线及桩身轴力分布曲线。通过试验结果曲线的分析,发现:19 200 kN荷载作用下,试桩基本处于线弹性变形阶段,且桩顶沉降值较小,累计总沉降值7.74 mm;卸载线为一缓变型曲线,卸载后的最终沉降值为2.9 mm;在各级荷载作用下桩身轴力在粘土层及卵石层变化相对较均匀且斜率很小,但从12 m处(卵石层与强风化泥质粉砂岩交界处)开始急剧减小,桩端轴力较小,几乎为零,这说明基桩的嵌岩段承担了绝大部分桩顶荷载。上述试验结果,可以为该地区桥梁桩基的设计与施工提供参考依据。
Tong-ping high way is the first stage of ＂five longitudinal and seven horizontal＂ highway network＇ first longitudinal（ping-ru high way） in hunan planning.In order to explore the foundation pile vertical load bearing mechanism of tong-ping high way shang-ping lie-luo jiang-te bridge,select one of k56＋295 shang-ping lie-luo jiang-te bridge＇ 22# pier as test pile foundation,through experiment design,test equipment of buried along with loading and test,carry out the static load test,get the test pile of pile top Q-s curve and pile body axial force distribution curve.Through the test results curve analysis,found that： test pile is always in the linear elastic stage,pile top settlement value is small,the total settlement value of 7.74 mm.Unloading curve present changes slowly,unloading after completion of the final settlement is 2.9 mm.In the various loads axial force in the clay layer and pebble bed change uniform and slope is smaller,but from 12 m place（pebble layer and strong weathering argillaceous siltstone border） began to decrease sharply,until the end of the pile,pile end axial force is small,is almost zero,this shows socketed section bear most of the pile top load.The above test results,can provide a reference basis for this area of the bridge pile foundation design and construction.
出处
《公路工程》
北大核心
2012年第6期6-10,共5页
Highway Engineering
关键词
桥梁工程
桩基础
静载试验
Q—s曲线
弹性模量
bridge engineering
pile foundation
static load test
Q-s curve
modulus of elasticity
