Optimization Test on Navigable Flow Conditions at Confluence of Xinpingshui Tributary of Pinglu Canal

doi:10.11988/ckyyb.20231349

Abstract

Abstract:

The navigation flow conditions of canal directly impact ship navigation safety. Channel regulation measures can effectively alleviate unfavorable flow conditions. In the Pinglu Canal project, after the original channel was widened and deepened, a significant bottom elevation difference emerged between the canal and the tributaries along the original river course. These tributaries, entering the confluence with a large drop, adversely affect the navigable flow conditions of the mainstream. Xinpingshui is a representative tributary with a large riverbed elevation difference and a wide intersection angle with the canal. To ensure smooth navigation in the Pinglu Canal, we conducted fixed-bed model tests to investigate the navigable flow conditions at the confluence of the Xinpingshui tributary and the main canal. Based on the test results, we proposed corresponding regulation measures. Results indicate that, on the basis of the canal construction, widening both the main and tributary channels and installing additional dissipation pools and diversion dikes at the tributary mouths significantly improve the navigational flow conditions under various flood scenarios. The findings of this study can serve as a reference for improving navigation channels in similar river reaches.

Key words: Pinglu Canal, channel current, tributary inlet, navigation flow condition, fixed-bed physical model

CLC Number:

U617

YANG Ya-nan, ZHOU Shi-liang, WANG Yun-li, YAN Chun-hao, FAN Hao-dong, XIANG Mei-tao. Optimization Test on Navigable Flow Conditions at Confluence of Xinpingshui Tributary of Pinglu Canal[J]. Journal of Changjiang River Scientific Research Institute, 2025, 42(3): 92-98.

Figures/Tables 14

Fig.1 River regime of the Xinpingshui tributary of the Pinglu Canal

Fig.2 Layout of the model

Fig.3 Velocity field measuring instruments

Table 1 Work conditions of the model test

工况	干流流量/ (m³·s^-1)	新坪水流量/ (m³·s^-1)	钦江尾水水位/m	运河尾水水位/m
1	752	547	21.04	10.45
2	1 489	704	23.59	11.86

Table 2 Validation results of the model water level

水尺编号	原型水位/m	模型水位/m	水位差/m
1^#	16.65	16.72	0.07
2^#	15.56	15.52	-0.04
3^#	15.56	15.54	-0.02
4^#	15.53	15.58	0.05
5^#	15.52	15.53	0.01
6^#	15.15	15.23	0.08

Fig.4 Verification of the average vertical velocity distribution of measured sections

Fig.5 Water levels and specific declines of the mainstream in current flow conditions

Fig.6 Velocity field in the confluence area of the mainstream and tributary in current flow conditions

Fig.7 Layout of the model in each design

Fig.8 Water levels and specific declines of the mainstream in different designs

Fig.9 Velocity field in the confluence area of the main-stream and tributary in the design program

Fig.10 Velocity field in the confluence area of the main-stream and tributary in optimization program 1

Fig.11 Velocity field in the confluence area of the main-stream and tributary in optimization program 2

Table 3 Summary of regulation results of each program

方案	工况	最大水面比降/‰	最大纵向流速/ (m³·s^-1)	最大横向流速/ (m³·s^-1)
设计	1	0.93	1.97	0.69
设计	2	—	2.10	0.82
优化1	1	1.54	1.88	0.64
优化1	2	2.34	2.40	0.73
优化2	1	0.88	1.41	0.48
优化2	2	1.21	1.97	0.44

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