软弱地层钢管桩嵌岩深度及侧阻力特性  

Rock socketed depth and lateral resistance characteristics of steel pipe in soft rock

作　　者：邱敏 胡睿杰 王超[1,2,3,4] 宋喜硕 QIU Min;HU Rui-jie;WANG Chao;SONG Xi-shuo(CCCC Second Harbor Engineering Co.,Ltd.,Wuhan 430040,China;Key Laboratory of Large-span Bridge Construction Technology,Wuhan 430040,China;Research and Development Center of Transport Industry of Intelligent Manufacturing Technologies of Transport Infrastructure,Wuhan 430040,China;CCCC Highway Bridge National Engineering Research Centre Co.,Ltd.,Beijing 10011,China)

机构地区：[1]中交第二航务工程局有限公司,湖北武汉430040 [2]长大桥梁建设施工技术交通行业重点实验室,湖北武汉430040 [3]交通运输行业交通基础设施智能制造技术研发中心,湖北武汉430040 [4]公路长大桥建设国家工程研究中心,北京100011

出　　处：《水运工程》2021年第2期160-165,共6页Port & Waterway Engineering

摘　　要：对于软弱岩层中的打入桩,目前尚无公认的方法评估桩侧阻力。针对巴拿马Amador邮轮码头航站楼嵌岩钢管桩基础,开展了9组桩基动力测试,采用波动方程分析方法获取桩侧阻力。研究了地层中桩侧阻力分布规律、岩层中桩侧阻力与单轴抗压强度的关系。得出如下结论:1)侧阻力分布曲线均呈抛物线形式,可以明显区分出软黏土、粉质砂土、强风化岩、中风化岩4个地层。将曲线跌落后的部分定义为嵌岩段,据此得到桩A-4嵌岩深度为6 m、其他桩嵌岩深度为4 m,均满足设计最小嵌岩深度3 m的要求。2)岩层桩侧阻力-抗压强度(UCS)曲线均呈指数分布,而非线性分布。3)软弱岩层中,侧阻力起主导作用。同一UCS值,泥质粉砂岩中桩侧阻力明显大于玄武岩。4)随着UCS增大,岩体的自稳能力逐渐增强,摩擦系数逐渐转变为影响侧阻力的主导因素。UCS增大到一定数值后,桩侧阻力趋于稳定。5)获得了岩层桩侧阻力-抗压强度关系式,为估算场地岩层中桩侧阻力提供了依据。For driven piles in the soft rock stratum,there is currently no accepted method to evaluate the side resistance.For the rock socketed steel pipe pile foundation of Panama Amador cruise terminal,nine groups of dynamic tests of pile foundation have been carried out,and the side resistance of pile has been obtained by wave equation analysis method.The distribution law of pile side resistance in stratum and the relationship between pile side resistance and uniaxial compressive strength in rock stratum has been studied.The conclusions are as follows:1)The distribution curve of side resistance is in parabola form,and four strata can be distinguished obviously,which are soft clay,silty sand,strongly weathered rock,and moderately weathered rock.The part after the curve falls is defined as the rock socketed section.Based on this,the rock-socking depth of pile A-4 is 6 m,and the rock-socking depth of other piles is 4m,which meets the design minimum rock-socking depth of 3m.2)The pile side resistance compressive strength(UCS)curve of rock stratum is exponential distribution,and non-linear distribution.3)In the soft rock stratum,the side resistance plays a leading role.With the same UCS value,the pile side resistance in argillaceous siltstone is obviously larger than basalt.4)With the increase of UCS,the self-stability of rock mass gradually enhances,and the friction coefficient gradually changes into the dominant factor affecting the side resistance.After UCS increases to a certain value,the pile side resistance tends to be stable.5)The relationship between pile side resistance and compressive strength in the rock stratum is obtained,which can provide a basis for estimating pile side resistance in the rock stratum.

关 键 词：巴拿马 嵌岩桩 软弱岩层 侧阻力 波动方程 

分 类 号：TU433[建筑科学—岩土工程] U656[建筑科学—土工工程]