吉林水利
吉林水利
길림수리
JI LIN WATER RESOURCES
2015年
2期
18-21
,共4页
交汇处堤防%渗透特性%设计洪水位%洪水成因
交彙處隄防%滲透特性%設計洪水位%洪水成因
교회처제방%삼투특성%설계홍수위%홍수성인
dike located Confluence%permeability%design flood level%Flood Causes
为揭示不同洪水成因下河流交汇处堤防渗透特性的差异,依托忆马溪流域双河口交汇河段,首先根据伯努利方程推求干、支流上游分别或同时遭遇10年一遇设计洪水时河流交汇处各特征剖面的设计洪水位及水深,在此基础上以交汇处相应特征剖面堤防为研究对象,采用有限单元法对三种设计洪水位下河流交汇处堤防迎水面特征点孔隙水压力、最大渗透比降等渗透特性进行仿真模拟。仿真结果如下:(1)支流遭遇10年一遇设计洪水时,干流水位、水深高于支流,导致干流堤防孔隙水压力、最大渗透比降偏大,同时干流出口处最易发生渗透破坏;(2)干流单独遭遇或干支流同时遭遇10年一遇设计洪水时,支流水位、水深高于干流,导致支流堤防孔隙水压力、最大渗透比降偏大,此时支流出口处最易发生渗透破坏。由此可见,进行堤防防洪抢险时应根据不同洪水成因突出相应的重点防护区。
為揭示不同洪水成因下河流交彙處隄防滲透特性的差異,依託憶馬溪流域雙河口交彙河段,首先根據伯努利方程推求榦、支流上遊分彆或同時遭遇10年一遇設計洪水時河流交彙處各特徵剖麵的設計洪水位及水深,在此基礎上以交彙處相應特徵剖麵隄防為研究對象,採用有限單元法對三種設計洪水位下河流交彙處隄防迎水麵特徵點孔隙水壓力、最大滲透比降等滲透特性進行倣真模擬。倣真結果如下:(1)支流遭遇10年一遇設計洪水時,榦流水位、水深高于支流,導緻榦流隄防孔隙水壓力、最大滲透比降偏大,同時榦流齣口處最易髮生滲透破壞;(2)榦流單獨遭遇或榦支流同時遭遇10年一遇設計洪水時,支流水位、水深高于榦流,導緻支流隄防孔隙水壓力、最大滲透比降偏大,此時支流齣口處最易髮生滲透破壞。由此可見,進行隄防防洪搶險時應根據不同洪水成因突齣相應的重點防護區。
위게시불동홍수성인하하류교회처제방삼투특성적차이,의탁억마계류역쌍하구교회하단,수선근거백노리방정추구간、지류상유분별혹동시조우10년일우설계홍수시하류교회처각특정부면적설계홍수위급수심,재차기출상이교회처상응특정부면제방위연구대상,채용유한단원법대삼충설계홍수위하하류교회처제방영수면특정점공극수압력、최대삼투비강등삼투특성진행방진모의。방진결과여하:(1)지류조우10년일우설계홍수시,간류수위、수심고우지류,도치간류제방공극수압력、최대삼투비강편대,동시간류출구처최역발생삼투파배;(2)간류단독조우혹간지류동시조우10년일우설계홍수시,지류수위、수심고우간류,도치지류제방공극수압력、최대삼투비강편대,차시지류출구처최역발생삼투파배。유차가견,진행제방방홍창험시응근거불동홍수성인돌출상응적중점방호구。
In order to reveal the differences of seepage characteristics of dikes at River confluence under flood levels of different origins,taking the Shuanghe Confluence of Yimaxi watershed as an example,the design flood levels and depths of River confluence at several typical sections are formulated according to the Bernoulli e-quation under different floods caused by occurrence of 10 years in upstream of mainstream and branch stream separately and at the same time.On the basis of these design flood levels ,the pore pressure of dike heel and maximum seepage gradient at the corresponding typical dike sections under the three different floods are simu-lated by the finite element method at three design flood levels.The simulation results are as follows:(1)When tributary stream encounters the design flood with the occurrence of 10 years ,the level and depth of main stream are higher than tributary streams;pore water pressure and maximum seepage gradient of the dike at mainstream are greater,and it is easiest to cause a failure by seepage at the exit of main stream;(2)When main stream suffered alone,or main stream and tributary streams encounter the design flood with the occurrence of 10 years at the same time,the level and depth of water in tributary stream are higher than main streams;a tributary of the embankment leading to pore water pressure drop larger than the maximum penetration ,then the most likely to occur at the outlet tributary infiltration and sabotage.Thus the conduct dike flood rescue should highlight the appropriate focus of protection ,depending on the causes of the flood zone.