Compressive tests on piles socketed in gravelly sediments were conducted. Six bored piles and four barrette piles, with or without base grouting, were studied using back-analysis. A spline function was used to fit the measured data for pile load along the depth. Using the fitted spline function and assuming that behaviour at the pile–soil interface is hyperbolic, back-analysis was used to determine the model parameters by calibrating the design value of β (the product of the coefficient of horizontal soil stress and the value of the tangent of the effective angle of shearing resistance of the soil–shaft interface) and comparing the results of back-analysis and the measured data. The results of this comparison revealed that the results of back-analysis were sensitive to the measured data. A back-calculated β value that is, in general, larger than that found by current methods was obtained.

中文翻译：

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对砾石沉积物中钻孔和发夹桩的压缩载荷测试

对嵌在砾石沉积物中的桩进行了抗压测试。使用反向分析研究了六种钻孔桩和四根发夹桩，有无基层灌浆。样条函数用于拟合沿深度的桩荷载测量数据。使用拟合的样条函数并假定桩-土界面处的行为是双曲线的，通过校正β的设计值（水平土应力系数与土的应力值的乘积），使用反分析来确定模型参数。土-轴界面的抗剪有效角的正切值），然后将反分析结果与实测数据进行比较。比较的结果表明，反向分析的结果对测得的数据很敏感。反向计算通常获得的β值要大于当前方法得出的值。