碎石土土体性状对桩基水平承载能力的影响  

EFFECT OF GRAVEL-SOIL CHARACTERS ON LATERAL BEARING CAPACITY OF PILE FOUNDATION

作　　者：康舜 赵其华[1,2] 彭社琴[1,2] 刘斌 陈继彬[1,2,5] KANG Shun;ZHAO Qihua;PENG Sheqin;LIU Bin;CHEN Jibin(State Key Laboratory of Geo Hazard Prevention and Geo Environment Protection (Chengdu University of Technology),Chengdu 610059;College of Environment and Civil Engineering Chengdu University of Technology,Chengdu 610059;College of Water Resources and Hydropower,Sichuan University,Chengdu 610065;General Station of Geological Environment Monitoring of Jiangxi Province,Nanchang 330095;China Southwest Geotechnical Investigation & Design Institute,Chengdu 610059)

机构地区：[1]地质灾害防治与地质环境保护国家重点实验室(成都理工大学),成都610059 [2]环境与土木工程学院(成都理工大学),成都610059 [3]四川大学水利水电学院,成都610065 [4]江西省地质环境监测总站,南昌330095 [5]中国建筑西南勘查设计研究院,成都610059

出　　处：《工程地质学报》2019年第3期559-568,共10页Journal of Engineering Geology

基　　金：国家自然科学基金面上项目(41272333);国家重点基础研究发展计划(2011CB013501)资助~~

摘　　要：桩基作为一种广泛使用的基础形式,其在如地震荷载、风荷载下的水平承载力确定十分重要。桩基水平承载能力主要由桩身及土体性质控制,而土体性质中密实度和含石量是影响碎石土场地上桩基水平承载能力的主要因素。为明确碎石土场地土性对桩基水平承载能力的影响,在室内开展5组不同土体密实度和含石量下的水平场地单桩水平静载试验,以此模型试验数据计算所得的临界荷载、极限荷载、水平扩散角、计算宽度和水平抗力系数的比例系数m值等为指标评价土体密实度和含石量对桩基水平承载能力的影响。试验结果表明增大密实度和含石量对各指标均有提升效果,但相比之下,密实度对各项指标的提升效果均明显优于含石量。综合考量下,碎石土密实度和含石量的增大均对桩基水平承载力有提升作用,但土体密实度的提升作用更明显。故对水平承载力要求较高的碎石土上桩基工程的选址中,应优先选择密实度较大的场地。The lateral loading capacity of various foundations are facing different requirements when they are applied to more and more fields.As the widespread usage of foundation forms,pile foundation plays an important role in various engineering.The two kinds of bearing capacity of pile foundation include vertical bearing capacity and lateral bearing capacity.Lateral capacity plays a crucial role in many situations in order to determine the stability under the seismic load and wind load specially.The lateral bearing capacity of pile foundation is mainly affected by pile and soil properties while the compactness and stone content of soil are the major factors to influence the lateral bearing capacity of the pile foundation on the gravel soil.This paper aims to clarify the influence of soil properties from the gravel soils on the lateral bearing capacity of pile foundations.It carries out 5 groups of indoor tests on static lateral loading test of single piles under different soil compactness and stone content.To achieve the expectation of the test,the relationship of piles top displacement and lateral load is recorded.Their curves are plotted for the relationship with different compactness and stone content.Furthermore,critical load and ultimate load are found from these curves.As the load increases,the development of soil fissures surrounding the pile is recorded by taking photos and sketching in the progress of loading and writing explanations.The stress-strain process is divided into three parts according to the curve of piles top displacement and lateral load and the development of soil fissure surrounding the pile.Lateral radial angle is obtained from the soil fissure angle surrounding the pile and is another important index to explain the lateral bearing capacity of pile foundation.According to the principle of horizontal diffusion,the effective calculating width in different soil properties is calculated using the lateral radial angle.Finally,the formulation of effective calculating width which provided by specific

关 键 词：碎石土 桩基 计算宽度 M值 水平承载力 

分 类 号：TU473.11[建筑科学—结构工程]