Chinese Academy of Sciences

Tsinghua University

Xiaoqing Chen

Jiangang Chen

Yong You

Wanyu Zhao

Tao Wang

Shuai Li

Peng Cui

Huayong Chen

Jinbo Tang

Yuhua Zou

Xian Wang

Kai Huang

Wei Zhong

Kai Hu

Gongdan Zhou

Dongri Song

Hao Jiang

Yitong Bai

Daozheng Wang

Wenrun Liu

Xinglong Gong

Yifei Cui

Fenghuan Su

Lu Zneg

Fangqiang Wei

Deji Li

The invention provides a method for preventing super large-scale floods and debris flows. First, the scale corresponding to certain standard floods in the watershed is evaluated based on field investigations and historical data. Second, the design standards of the system are chosen based on the prevention of super large-scale floods, and the design standard of critical control engineering is further determined. Finally, the design methods of check dams with different functional zones are proposed according to the design standards of critical control engineering. The invention allows part of the key control dam to fail under safe operating conditions of the entire system by increasing the cross-sectional areas and the flow discharges. The unbroken foundation of the dam can effectively control the channel entrainment and regulate the cross-sectional discharge. The design is helpful in mitigating giant floods and debris flows, thus protecting downstream infrastructures.

Method for prevention and control of super large-scale floods and debris flows

The method for preventing and controlling glacial lake outbreak flood and related debris flows by the present invention is mainly controlling the scale of the floods by separating water and rocks and dispersing its energy step by step. The cascading amplification effects of floods can be reduced by controlling the initiation of source material with energy dissipation by using ground sills, groups of piles, and placed large stones and prefabricated artificial structures. The diversion dam built in the downstream area discharge floods in different layers, which can quickly guide water to the main river. The preconstructed engineering system can be used in a timely manner to prevent and control floods and debris flows induced by a sudden outburst of glacial lakes in areas with important facilities and inhabitants enduring the risk of natural hazards. Prevention and control systems can separate floods and debris flows and dissipate their energy. The groups of ground sills and check dams gradually dissipate the energy of floods, prevent high-energy boulders, and control the initiation of source materials in the channel and bank. Moreover, the systems can also separate the water and rocks in dilute debris flows or debris flows with high bulk densities but low viscosities. The diversion dams also enhance the separation function and keep the flood and debris flow discharge in the lower and upper channel to the main river.

Prevention method for floods and debris flows caused by glacial lake outbursts

A method for forming a test flume usable in hydraulic engineering and debris-flow hazard mitigation is provided. The test flume has a foundation flume and an expansion flume. The expansion flume has a lower edge connected to an upper edge of the foundation flume. A hydraulic radius of the test flume is determined based on a model test. A width of the foundation flume is selected based on a size of the test site of the model test. A coefficient is obtained and a width of the test flume is obtained. A cross section curve equation of the expansion flume is obtained based on the hydraulic radius of the test flume, the coefficient, the width of the test flume and the width of the foundation flume. The test flume is formed based on the cross section curve equation of the expansion flume.

Designing method of test flume with special-shaped cross section and application thereof

ABSTRACT OF THE DISCLOSURE A method for regulating and controlling discharge flow of a dammed lake includes steps of: (S1) estimating a most dangerous discharge condition; (S2) based on the most dangerous discharge condition, calculating a structural internal force of the steel flexible net; (S3) based on the internal force of the steel flexible net, calculating an anti-slide embedded depth at two sides of the steel flexible net; (S4) based on the most dangerous discharge condition, manually excavating a channel; and (S5) based on the anti-slide embedded depth at the two sides of the steel flexible net, embedding the steel flexible net into a barrier dam. According to the present invention, the steel flexible net is laid on the upstream slope of the barrier dam, two sides of the steel flexible net is embedded into the slope body with gravels of the barrier dam, and cooperates with the channel for usage.

Method for regulating and controlling discharge flow of dammed lake

An asymmetric debris-flow discharge channel is provided. The debris-flow discharge channel has a main drainage channel for discharging a debris flow and an auxiliary channel provided outside of the main drainage channel. The side walls of the auxiliary channel are integrated with the side walls of the main drainage channel or provided outside of the side walls of the main drainage channel. The debris-flow discharge channel also has a break section integrated into a side wall of the auxiliary channel. The top width of the break section is equal to the top width of the auxiliary channel A method for designing and building the asymmetric debris-flow discharge channel is also provided, which provides a lower initial cost, higher safety performance, and a lower maintenance cost at the operating stage.

Asymmetric debris flow drainage trough and design method and application thereof

A method of designing a box-type energy-dissipating section of a box-type energy-dissipating mudflow diversion flume. Firstly, the longitudinal gradient J of the flume and the roughness coefficient n 0 of a fully-lined flume bottom () are determined. Then, the parameters of the box-type energy-dissipating section are set, and related parameters are substituted into a formula for calculation, so that the overall roughness coefficient n of the flume is obtained. Further, the flow velocity of the mudflow is calculated by means of the Manning formula. Finally, the flow velocity of the mudflow is compared with the non-scouring and non-silting velocity allowed by the flume, and the design value of the box-type energy-dissipating section is obtained through final optimization. The method factors in the longitudinal gradient J of the flume, the length L of the box-type energy-dissipating section, the width b of the box-type energy-dissipating section, and the average diameter D of filler stones. With the method, the overall roughness coefficient n of the flume under different design conditions can be determined reasonably, so as to further implement the optimized design of the box-type energy-dissipating section of the box-type energy-dissipating mudflow flume. Further provided is an application of the method of designing a box-type energy-dissipating section of a box-type energy-dissipating mudflow flume.

Method of designing box-type energy-dissipating section of box-type energy-dissipating mudflow diversion flume, and application

A method for planning and designing a debris flow drainage channel is provided. The position and total length of the drainage channel and a longitudinal slope of a gully bed of the drainage channel are determined. An inlet section, an outlet section and an acceleration section of the drainage channel are formed as fully lined channel type. After determining the length of the inlet section and the included angle between the side wall of the inlet section and the main channel, the length of the outlet section and the included angle between the side wall of the outlet section and the main channel, and the length of the acceleration section, the channel type and the length of the main channel section are also determined.

Method for planning and designing debris flow drainage channels and applications thereof

A debris flow drainage channel is provided. The debris flow drainage channel is applicable to debris flows with large gully bed longitudinal slopes. The debris flow drainage channel has an upstream step section and a downstream step section. The debris flow drainage channel also has a step pool disposed between the upstream step section and the downstream step section. The pool section has a cable net cage bottom protection, a cable net cage buffer layer and block stones.

Debris flow drainage channel with step pool structure and its applications

The invention discloses a debris-flow prevention method by controlling debris-flow magnitude and avoiding to block main river. This method first adopts the drainage works for delivering debris flow in corporation with the transport of the main river; if the drained sediment cannot be transported by the main river, the blocking works are adopted; and if the sediment still exceeds the delivering capacity, the deposit stopping works are adopted. Compared with the prior art, this invention makes full use of the main river's transport capacity, gives priority to dredging and also reasonably distributes the sediment and deploys the engineering system, so as to realize the safe discharge of debris flow, and avoid the secondary disaster of 'barrier lake' caused by the blocking of main river due to excessive discharge of debris flow and fully guarantee the safety of mountain towns, major projects and infrastructure located at the mouth of debris flow gully.

Debris-flow prevention method by controlling debris-flow magnitude and avoiding to block main river

Growing community of inventors

Sichuan, China

Xiaoqing Chen