Analysis Of The Seepage And Stability Of Dikes At River Confluence Under Flood Peak Staggered

The water level fluctuation of interchange river influence by both tributaries floods.Tributaries flooding due to storm center location and river slope different,the time of peak form will different,eventually leading to the time of peak arrival Interchange stagger.Peak stagger will cause the water level continuous fluctuation.At the dike within,the saturated zone and unsaturated zone continuous transformation,forming a unsteady seepage field,the pore water pressure and Seepage gradient changing will influence the embankment stability.Therefore,and this phenomenon is particularly prominent for mountain rivers,rapid fluctuations of the water level of rivers in mountainous cause stability abnormal changes in the dike.Therefore,for the mountain rivers,study on the seepage characteristics variation of dikes at river confluence under flood peak staggered,and analysis of the instability mechanism of dike,provide technical support for the normal operation of the dike.This article combined with Chen stream and Lu stream Interchange dike,combined use of the finite element method and limit equilibrium method,study on the seepage and stability of dikes at river confluence under flood peak staggered,Main consider the tributaries peak stagger time and the speed of water level fluctuation to the seepage and stability of dikes,analysis the process of saturated and unsaturated seepage of dike,Systematic study the seepage and stability of dikes at river confluence under flood peak staggered,and pointed out the may indicate instability time period of dike.Provide a reference for future interchanges dike safe operation and warning.Study for the following several issues:(1)Analysis of internal and external factors affecting the propagation time of flood,for the project area data of meteorological and hydrological,point out that the main factors influencing the tributaries flood propagation time is rainstorm center location.While tributaries typical peak load shifting time 0,5,10 hours,at each peak shifting time,analysis the water level fluctuation laws of the confluence at the rivers.(2)According to the unsteady-unsaturated seepage theory,using the finite element method,Simulation the seepage field of dike under different tributaries intersection,the key analysis the pore water pressure and seepage gradient change rule at corresponding condition.Point out that pore water pressure at inside the dike change with the peak load shifting,water level fluctuation velocity and position of dike,but seepage gradient major change with the water level fluctuation velocity.(3)Base on the saturated-unsaturated seepage calculate.Using limit equilibrium method,computing the stability of the dike under flood peak staggered,the key analysis the regular of dike stability,pointed out the probably destabilize time of dike.