铁路工程不同地质单元路桥分界高度的研 究简

路桥分界高度是以桥代路的临界高度，小于此高度以路基通过，大于此高度则以桥梁通过。但在同一地貌、地质单元地段，是采用路基通过，还是以桥代路通过？此文选择不同类型的地貌、地质单元和段落，针对不同的设计阶段，对路桥分界高度的影响因素进行分析。并以某铁路工程为例，对不同地质单元的路基、桥梁分界高度和技术经济指标进行比较，通过比较，路桥分界高度每增减1m，每桥梁公里造价指标受路桥分界高度的影响较小，每路基公里造价指标受路桥分界高度的影响较大，一般分界高度应控制在6rn，个别情况下可按7m控制。

Research on Subgrade and Bridge Boundary of Railway Engineering Different Geological Unit

Subgrade and bridge boundary height is critical height, the subgrade is used under the height and the bridge is used over the height. But at the same landform, geologic unit location, how to choose is a prob- lem. This article choose different types of geomorphology, geological units and paragraphs, according to different design stage, analyzes the influence factors of subgrade and bridge boundary height. Taking a railway engineering as an example, the boundary between roadbed and bridge height and technical and e- conomic index of different geological units were compared. Through the comparison, it shows that in- creasing or reducing 1 km, the cost index per bridge kilometer was influenced less by subgrade and bridge boundary height and the cost index per subgrade kilometer was influenced more by subgrade and bridge boundary height. Height of general boundary should be controlled in 6 m, individual cases could be controlled by 7 m.