高速铁路沉降直接关系到高速铁路的安全运营和舒适度,而计算深度(即压缩层厚度)是能否准确计算沉降量的关键。以京沪高速铁路天津段和河北沧州段大桥基础为例,分别进行了现场试验和沉降量的理论计算。现场试验采用液位沉降计和单点沉降计联合监测的方法,得到总沉降量和不同深度土层的压缩量,根据不同深度每延米的压缩量确定压缩层厚度;以3个代表性工点(DK124、DK152、DK240)为例来理论计算其沉降量,经过比较分析得出,需同时满足以下两个条件才可确定压缩层厚度:一是某深度处土层满足压缩层厚度确定方法σi<0.1σzi;二是在该深度以下,土层相临深度间均有Δs/Δh<0.1 mm/m的土层深度。这样既考虑了应力对沉降的影响,也考虑了各土层的应变对沉降的影响。将理论计算值与现场监测数据进行对比,吻合较好。 The settlement of high-speed railway is directly related to the safe operation and comfort of high-speed railway. Calculating the depth (ie the thickness of compression layer) is the key to accurately calculate the settlement. Taking the foundation of Tianjin-Beijing-Shanghai high-speed railway and Cangzhou section of Hebei as an example, the theoretical calculation of field test and settlement are respectively carried out. The field test uses the method of combined monitoring by liquid level sedimentation and single point sedimentation to obtain the total settlement and the amount of compression in different depths of soil layers. The compression layer thickness is determined according to the compression amount of each meter in different depths. Three representative workers (DK124, DK152, DK240) as an example to theoretically calculate the settlement, after a comparative analysis, we must meet the following two conditions to determine the compressible layer thickness: First, the depth of a layer to meet the compressive layer thickness to determine the method σi <0.1σzi; and secondly, depths of soil below Δs / Δh <0.1 mm / m below the depth and between adjacent depths of soil. This not only considers the effect of stress on settlement, but also takes into account the influence of strata on settlement. The theoretical calculation and field monitoring data for comparison, good agreement.