MIKE21模型在老哈河铁路桥防洪影响评价中的应用

Application of MIKE 21 model in flood control impact assessment for Laohahe railway bridge

新建赤峰至京沈高铁喀左站铁路工程跨越老哈河。为研究工程对河道行洪的影响,应用MIKE21模型模拟建桥后的河道水流,进而进行防洪影响评价。根据老哈河上游4处参证水文站推求桥址处设计洪水。采用RIEGL三维激光扫描仪测量河道地形,结合1:1万地形图处理后,采用三角形网格对计算区域进行网格划分。对糙率等参数率定后,采用MIKE21模型进行模拟计算。计算结果表明,老哈河铁路桥修建后壅水高度较小,流场变化不大,对河道行洪安全影响较小。实践证明应用MIKE21模型模拟河道水流其效果良好,合理的评价结果为工程的防洪安全提供了保障。在实践中应做好对糙率等参数的率定,以保证模型的正确运行。

The new railway project from Chifeng City to Kazuo station of Jingshen high-speed railway will cross the Laohahe River. To study the influence of the project on the river course flood passing, the MIKE 21 model is used to simulate the river flow after the construction of the bridge and then the flood control impact are evaluated. The design flood at the bridge site are calculated based on the data of 4 reference hydrologic stations at the upstream of the Laohahe River, the RIEGL 3 D laser scanner is used to survey the river terrain and the data are process combined with the 1:10,000 topographic map, the calculation area is divided by using the triangulation network. After finishing the parameters calibration, such as roughness coefficient, the MIKE 21 model is used to simulation and calculation. The calculation results show that after the construction of the Laohahe railway bridge, the height of the backwater is low and the change of the flow field is small, the influence of flood passing on the bridge safety is small. The practice proves that the MIKE 21 model has good simulation effect and the reasonable assessment result could provide guarantee for the project flood control safety. The calibration of the parameters, such as the roughness coefficient, should be well done in the practice to ensure the correct operation of the model.