CAJ | 학술논문

采用荷载-位移联合搜索方法，对于饱和软黏土地基上裙板式桶形基础在水平荷载H、力矩M与扭矩T的非共面复合加载条件下的稳定性进行了比较系统的三维有限元分析，主要探讨了在不同荷载空间内桶形基础的破坏包络轨迹。在分析中，地基土服从基于Tresca屈服准则的理想弹塑性本构关系。计算结果表明，与传统共面复合加载情况相比，非共面复合加载条件下桶形基础的破坏包络面形状有较大差异。非共面复合加载情况下，包络面形状不依赖于基础埋深比，可用简单的圆或椭圆方程进行描述。根据有限元计算结果，将已有的三自由度破坏包络面方程扩展到六自由度复合加载空间内，进而初步建议了一个六自由度破坏包络面方程，并对于实际工程中常用的桶形基础埋深比，给出了方程中偏心度参数取值的确定方法。该方程可用来合理评价复杂荷载条件下软黏土地基上桶形基础承载力。
채용하재-위이연합수색방법，대우포화연점토지기상군판식통형기출재수평하재H、력구M여뉴구T적비공면복합가재조건하적은정성진행료비교계통적삼유유한원분석，주요탐토료재불동하재공간내통형기출적파배포락궤적。재분석중，지기토복종기우Tresca굴복준칙적이상탄소성본구관계。계산결과표명，여전통공면복합가재정황상비，비공면복합가재조건하통형기출적파배포락면형상유교대차이。비공면복합가재정황하，포락면형상불의뢰우기출매심비，가용간단적원혹타원방정진행묘술。근거유한원계산결과，장이유적삼자유도파배포락면방정확전도륙자유도복합가재공간내，진이초보건의료일개륙자유도파배포락면방정，병대우실제공정중상용적통형기출매심비，급출료방정중편심도삼수취치적학정방법。해방정가용래합리평개복잡하재조건하연점토지기상통형기출승재력。
Using combined load-displacement searching method, the stability of skirted bucket foundations in saturated soft clay subjected to horizontal load (H), moment (M) and torque (T) non-coplanar combined loading is studied through three-dimensional finite element numerical analysis. The soft soil is assumed to be undrained and obeys elasto-perfectly plastic constitutive relationship following the Tresca failure criterion. The failure locus of bucket foundations in various loading spaces is investigated. The results show that the shape of failure envelopes of bucket foundations subjected to non-coplanar combined loading varies considerably from that under planar combined loading. Under non-coplanar combined loading, the shape of failure envelope does not depend on the aspect ratio of bucket foundations, which may be approximated as a circle or ellipse in normalized load space. Based on finite element analysis, the existing equation of failure envelope in three-degree-of-freedom loading condition is extended to the six-degree-of-freedom case, then an equation of failure envelope involving all six-degrees-of-freedom is suggested, which can be used to evaluate the bearing capacity of bucket foundations in soft soil under combined loading condition. Values of the eccentricity parameter in the proposed equation are also presented for a range of practical embedment ratios.