强度折减法判定桩基础极限荷载的尖点突变条件

发布时间：2018-06-17 16:16

本文选题：桩基础 + 极限荷载　；参考：《西南交通大学学报》2014年03期

【摘要】：为采用强度折减法判定桩基础的极限荷载,根据突变理论Zeeman机构、桩基础承载力泛函数和直剪试验原理,建立了桩基础承载力突变的临界条件和位移增量梯度与岩土材料剪应力的关系,进而提出利用尖点突变曲线判定桩基础极限荷载.算例分析结果表明:尖点突变曲线拐点出现后,曲线近似垂直于强度折减系数坐标轴,强度折减系数的微小增量将引起位移增量梯度陡增,说明岩土材料已发生塑性变形,拐点对应的强度折减系数即为极限荷载条件下的强度折减系数;由尖点突变曲线和折减系数位移曲线得到的桩基础极限荷载基本相同,但尖点突变曲线的拐点更明显,物理意义更清晰.
[Abstract]:In order to use the strength reduction method to determine the ultimate load of pile foundation, according to the catastrophe theory Zeeman mechanism, the universal function of pile foundation bearing capacity and the principle of direct shear test, The critical condition of the sudden change of pile foundation bearing capacity and the relationship between the displacement increment gradient and the shear stress of rock and soil material are established, and the limit load of pile foundation is determined by using the cusp catastrophe curve. The result of example analysis shows that the curve is approximately perpendicular to the axis of strength reduction coefficient after the inflection point of cusp abrupt change curve appears, and the small increment of strength reduction coefficient will cause a sharp increase of displacement increment gradient, which indicates that plastic deformation has occurred in geotechnical materials. The strength reduction coefficient corresponding to the inflection point is the strength reduction coefficient under the limit load condition, and the ultimate load of pile foundation obtained from the cusp catastrophe curve and the reduction coefficient displacement curve is basically the same, but the inflection point of the cusp catastrophe curve is more obvious. The physical meaning is clearer.
【作者单位】：后勤工程学院建筑工程系;
【基金】：国家自然科学基金资助项目(51178457) 重庆市自然科学基金院士专项基金项目(cstc2012jjys0001)
【分类号】：TU473.1

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