钢管桩-灌注桩复合支护下桩间土拱力学效应分析  

Mechanical effect analysis of soil arch between piles under composite support of steel pipe piles and cast-in-place piles

作　　者：王洪涛 刘容利 赵晓东 赵耀辉 赵万里 WANG Hong-tao;LIU Rong-li;ZHAO Xiao-dong;ZHAO Yao-hui;ZHAO Wan-li(School of Civil Engineering,Shandong Jianzhu University,Jinan,Shandong 250101,China;Key Laboratory of Building Structural Retrofitting and Underground Space Engineering,Shandong Jianzhu University,Jinan,Shandong 250101,China;Jinan Rail Transit Group Co.,Ltd.,Jinan,Shandong 250100,China;Shandong Institute of Geophysical and Geochemical Exploration,Jinan,Shandong 250013,China)

机构地区：[1]山东建筑大学土木工程学院,山东济南250101 [2]山东建筑大学教育部建筑结构加固改造与地下空间工程重点实验室,山东济南250101 [3]济南轨道交通集团有限公司,山东济南250100 [4]山东省物化探勘查院,山东济南250013

出　　处：《岩土力学》2025年第4期1228-1239,共12页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52374093);中国博士后科学基金(No.2022M711314);山东省自然科学基金(No.ZR2022ME088);济南市科研带头人工作室项目(No.202333054)。

摘　　要：为研究不同类型围护桩联合作用下基坑地层土体支护力学响应特征,以济南轨道交通4号线林家庄车站基坑工程为依托,针对现场首次采用的钢管桩-灌注桩复合支护形式,构造提出了复合桩作用下地层支护应力解析分析模型与计算方法,分析了不同地层深度与桩间距下地层内部最大主应力分布特征及成拱效应规律。在此基础上,根据最大主应力支护迹线与桩间土拱轴线关系,提出了钢管桩与灌注桩间隔布设下桩间成拱分析模型,由内拱与外拱共同承担地层侧向土压力,推导了合理桩间距S和荷载分担系数λ的理论公式,并讨论了钢管桩、灌注桩的承担荷载能力关系。最后,结合具体工程实例验证了土拱分析模型的有效性,分析了内摩擦角、黏聚力、桩径等不同参数对合理桩间距S和荷载分担系数λ的影响规律。研究结果表明:钢管桩-灌注桩复合支护下,合理桩间距S随着内摩擦角、黏聚力、桩径的增加而增大;荷载分担系数λ随着内摩擦角及黏聚力的增加而增大,相应的外拱承担荷载的能力逐渐增强;当其他参数不变,钢管桩直径增大时,外拱承担荷载能力会逐渐减小。In order to study the mechanical response characteristics of soil support of foundation pit under the combined action of different types of retaining piles.Based on the foundation pit project of Linjiazhuang Station,Line 4 of Jinan Rail Transit,and aiming at the composite support form of steel pipe pile and cast-in-place pile adopted for the first time on site,the analytical analysis model and calculation method of stratum support stress under the action of composite piles are proposed.The distribution characteristics of the maximum principal stress and the rule of arching effect under different formation depths and pile spacings are analyzed.On this basis,according to the relationship between the maximum principal stress support line and the soil arch axis between piles,an arch analysis model is put forward,in which the inner arch and the outer arch bear the lateral earth pressure together,the theoretical formulas of reasonable pile spacing S and load sharing coefficient λ are derived,and the load-bearing capacity relationship between steel pipe pile and cast-in pile is discussed.Finally,the effectiveness of the soil arch analysis model is verified with concrete engineering examples,and the influence of different parameters such as internal friction angle,cohesion force,and pile diameter on reasonable pile spacing S and load sharing coefficientλis analyzed.The results show that the reasonable pile spacing S increases with the increase of internal friction angle,cohesion force,and pile diameter under the composite support design.The load sharing coefficientλincreases with the increase of internal friction angle and cohesion,and the load bearing capacity of the outer arch gradually increases.When other parameters remain unchanged and the diameter of steel pipe pile increases,the load bearing capacity of outer arch will gradually decrease.

关 键 词：土拱效应 大主应力 桩间距 荷载分担系数 

分 类 号：TU473[建筑科学—结构工程]