岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2014年
2期
421-432
,共12页
竺明星%龚维明%徐国平%何小元
竺明星%龔維明%徐國平%何小元
축명성%공유명%서국평%하소원
桩基础%堆载%隔离桩%Laplace正逆变换%矩阵传递法
樁基礎%堆載%隔離樁%Laplace正逆變換%矩陣傳遞法
장기출%퇴재%격리장%Laplace정역변환%구진전체법
pile foundations%surcharge load%isolation piles%Laplace forward and inverse transformation%matrix transfer method
为分析大面积堆载作用下轴向受荷隔离桩的被动受力特性,首先从布辛奈斯克(Boussinesq)改进解出发,推导出各种形式堆载作用下水平附加压力的理论计算公式;在此公式基础上,从土体的运动和应力的传递方式入手,对考虑土拱效应的局部塑性变形理论进行改进,从而得到合理的隔离桩桩身被动荷载分布;最后,根据考虑土体局部塑性屈服及轴向荷载重力二阶效应影响的三参数 Winkler 弹性地基梁模型,建立桩身弹性段与塑性段的微分方程组,求解过程中采用矩阵传递法结合 Laplace 正逆变换的方法解得隔离桩桩身被动受力特性的数值解,并用试验数据进行验证。结果表明,数值解与模型试验实测值吻合较好,本研究中关于被动桩的求解方法具有较高的应用与参考价值。
為分析大麵積堆載作用下軸嚮受荷隔離樁的被動受力特性,首先從佈辛奈斯剋(Boussinesq)改進解齣髮,推導齣各種形式堆載作用下水平附加壓力的理論計算公式;在此公式基礎上,從土體的運動和應力的傳遞方式入手,對攷慮土拱效應的跼部塑性變形理論進行改進,從而得到閤理的隔離樁樁身被動荷載分佈;最後,根據攷慮土體跼部塑性屈服及軸嚮荷載重力二階效應影響的三參數 Winkler 彈性地基樑模型,建立樁身彈性段與塑性段的微分方程組,求解過程中採用矩陣傳遞法結閤 Laplace 正逆變換的方法解得隔離樁樁身被動受力特性的數值解,併用試驗數據進行驗證。結果錶明,數值解與模型試驗實測值吻閤較好,本研究中關于被動樁的求解方法具有較高的應用與參攷價值。
위분석대면적퇴재작용하축향수하격리장적피동수력특성,수선종포신내사극(Boussinesq)개진해출발,추도출각충형식퇴재작용하수평부가압력적이론계산공식;재차공식기출상,종토체적운동화응력적전체방식입수,대고필토공효응적국부소성변형이론진행개진,종이득도합리적격리장장신피동하재분포;최후,근거고필토체국부소성굴복급축향하재중력이계효응영향적삼삼수 Winkler 탄성지기량모형,건립장신탄성단여소성단적미분방정조,구해과정중채용구진전체법결합 Laplace 정역변환적방법해득격리장장신피동수력특성적수치해,병용시험수거진행험증。결과표명,수치해여모형시험실측치문합교호,본연구중관우피동장적구해방법구유교고적응용여삼고개치。
This paper aims at analyzing the passive mechanical characteristics of axially loaded isolation piles under large-scale surcharge loading. Firstly,the formulation for calculating lateral additional pressure with local surcharge is deduced based on the solution of improved Boussinesq. Then according to soil movement and stress transfer approach,the rational passive load distribution of isolation piles is obtained by improving local deformation theory of plasticity considering soil arching. Finally,differential equations of elastic and plastic regions of isolated piles are established by considering the gravity second-order effect caused by lateral load and yield of soil for tri-parameter Winkler elastic foundation beam model. Combining matrix transfer method with Laplace forward and inverse transformation,the numerical solution of passive mechanical features of isolation piles is obtained. Later,the proposed approach is verified by the test data. The results indicate that the numerical and measured results are in good agreement,and the proposed approach is applicable in engineering practice.