Abstract: The increment of the consumption of prime materials of the monolithic 30m span of the prestressed concrete T-beam model in the same safety reserve was obtained by improving the vehicle load level under the condition of unaltered stiffness. With the help of monadic linear regression and path analysis method, the quantitative relation between the consumption of prime materials (concrete, steel) of monolithic T-beam and the range of improving the vehicle load level was determined. The conclusion can help relevant departments to make decision about the plan of managing overloading and improving load.

Key words: bridge engineering;vehicle load, monolithic T-beam, unaltered stiffness, path analysis method

摘要： 在保持桥梁刚度不变的条件下，对构建的单片30 m跨径预应力混凝土简支T梁模型进行逐步提载，获取了相同安全储备下的材料增加量；采用一元回归与路径分析方法确定了车辆荷载等级提高幅度与单片T梁主要材料（混凝土、钢材）增加量之间的定量化关系。研究可作为相关部门治超与提载方案的决策依据。

关键词: 桥梁工程, 车辆荷载, 单片T梁, 刚度不变, 路径分析法