Method for regulating pebble shoal in intensified low-flow branching layout

Abstract

The invention discloses a method for regulating a pebble shoal in intensified low-flow branching layout. According to the method, a straight channel is opened to air traffic, a dredging and damming hybrid regulation measure is taken, a layout wherein a longitudinal dike and a spur dike are built on a low channel bar to intensify low-flow branching, flow returning is promoted, and the straight channel is moderately narrowed; a water damage control measure, where interlock blocks placed at the head of the middle longitudinal dike and the head of the spur dike under severe flow scouring are used for surface covering by coping, is taken. The method has the advantages that the longitudinal dike and the spur dike are bit on the channel bar, bed load can be driven to deposit on the channel bar, the channel bar is raised and widened, the river regime feature of the low-flow branching is intensified, flow returning is promoted, and stability of a low-flow channel is benefited; tests on movable bed models in straight channel recommendation schemes for Shenbeizui and Tonggutan show that the joint application of channeling and regulating structures for intensifying the channel bar branching leads to a good regulation effect, the structure of the head of the spur dike in which the interlock blocks are used for surface covering by coping is adopted, overall stability of a dam is enhanced, and the dam is well stable.

Description

technical field [0001] The invention belongs to the research field of waterway regulation, and in particular relates to a pebble shoal regulation method that strengthens the dry-water branch pattern. Background technique [0002] The Shenbeizui dangerous shoal in the upper reaches of the Yangtze River is located near Mituo Town, Lu County, Sichuan Province. The test section has a waterway mileage of 876-868 km, and the plane shape is a sharp turn of about 110°. The right bank of the transition section is a flat and open ancient river bed floodplain with a width of about 1000-1500m. There are rock plates such as Mituo Stone Wall, Jiutiaolong, Zhuershi, and Frog Rock on the banks of the middle and low water rivers, which narrow the dry water channel to the left bank of the entrance below the mouth of Shenbeizui. The 1200m-long moraine divides the channel into left and right troughs. The left trough is a curved branch channel with a narrow entrance bend and large longitudinal...

AI Technical Summary

Problems solved by technology

However, due to the limitation of the river regime, it is difficult to increase the bending radius of the curved branch channel, and the stability of the trench is poor.

The entrance of Shenbei mouth bends only 220m, and to meet the minimum bending radius requirement of 560m, a navigation channel must be arranged in the moraine head; to increase the bending radius of the middle section of the right channel in Tonggutan, dry water navigation channels must be arranged on the edge of the moraine wing in the center of the river; the above excavation The trough area is located in the sand conveying belt, and the floodplain water flow in the middle and upper section of the curved branch channel is weak in dispersing and scouring, and the trenching is also easy to silt, and the channel maintenance project is large

For example, in 1990, the waterway department rehabilitated the left trough of Shenbeizui Shoal, built a parallel dam to block the cross flow at the Saigan moraine, and dredged the entrance of the left trough to increase the bending radius. , the trough is silted and shallow, hindering navigation

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