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现有的桩承式路堤荷载传递计算方法主要依据3类土拱效应力学计算模型。由于宏观土拱形态观察的难度较大,现有计算方法普遍缺乏对不同填料与参数下拱效应传力机制以及宏观土拱拱形参数的深入探讨。采用自制的试验装置对砂填料桩承式路堤土拱效应模型进行探讨,进行了3组不同桩距比下3种填土高度的模型试验。模型试验装置配备了位移控制装置模拟与精确控制桩间土下沉,在下沉过程中连续、同步的采集土压力以及砂箱内部填料的照片,并通过摄影测量技术获取全场位移数据。通过对桩土应力比曲线特征以及曲线特征点所对应的填料颗粒位移图的综合分析,探讨了砂填料桩承式路堤拱效应传力机制,揭示了填料内部存在的初始三角形松动滑移面。基于此提出了初始三角拱力学计算模型,分析得到了滑移面角度随桩距比变化的规律,并利用滑移面夹角统计数据确定了拟合计算公式,通过力学推导建立了适用于砂填料桩承式路堤的桩土应力比计算方法。通过与Rogbeck法、BS8006法、Terzaghi法以及模型试验实测数据的对比,验证了计算方法的合理性。
The existing calculation method for load transfer of pile-supported embankment is mainly based on three types of soil arching effect mechanics calculation model. Due to the difficulty in observing macro-arches, the current calculation methods generally lack the in-depth discussion on the force transmission mechanism under different loadings and parameters and the arching parameters of macro-soil arching. The soil arching effect model of sand-filled piled embankment is discussed by using self-made test equipment. Three kinds of model tests of earth filling height under different pile-to-pile ratios are carried out. The model test device is equipped with a displacement control device to simulate and precisely control the soil subsidence between the piles. During the process of sinking, the continuous and synchronized collecting earth pressure and the photos of the packing inside the sand box are obtained. The displacement data of the whole field is obtained through the photogrammetry technology. Based on the comprehensive analysis of the stress-strain curve of pile-soil and the displacement map of the filler particles, the transmission mechanism of the sand-filled pile-supported embankment is discussed and the initial triangular loose slip surface is revealed. Based on this, the initial calculation model of the triangle arch mechanics is put forward. The law that the angle of the slip surface changes with the distance between the pile and the pile is analyzed and the fitting formula is established by the statistic data of the included angle of the slip surface. Pile - Soil Stress Ratio Calculation Method for Packed Piled Embankment. Compared with the Rogbeck method, BS8006 method, Terzaghi method and the experimental data of the model test, the rationality of the calculation method is verified.