【某双曲拱坝的泄水建筑物设计计算1200字】

某双曲拱坝的泄水建筑物设计计算目录TOC\o"1-3"\h\u21488某双曲拱坝的泄水建筑物设计计算 1123851.1泄水建筑物的组成与布置 1220471.2泄槽设计 1109161.2.1泄槽尺寸 1140931.2.2导墙尺寸 287901.3消能与防冲 3255001.3.1水舌挑距 3144261.3.2冲刷坑深度 3191031.3.3消能率计算 450621.4泄水孔口应力及配筋计算 41.1泄水建筑物的组成与布置泄水建筑物布置如枢纽概述1.2泄槽设计1.2.1泄槽尺寸1、坎顶高程=下游设计水位+（2~5m）=113.78+（2~5m）=115.18~118.78m取为118m。2、坎上水深hcT=hc+q2/(2gφ2hc2)式中：T——上游设计水位至坎顶的高差q——单宽流量φ=0.95对浅孔：T=186.34-118=68.34mQ=3391.37m3/sq=Q/(9.5×2)=3391.37/(9.5×2)=178.651m3/s68.34=hc+178.6512/(2×9.81×0.952×hc2)经试算得hc=5.352m；对中孔：Q=3032.14m3/sq=Q/(7.5×2)=3032.14/15=202.143m3/s68.34=hc+202.1432/(2×9.81×0.952×hc2)经试算得hc=6.082m得到坎上水深hc：浅孔5.352m；中孔6.082m3、反弧半径RR=(6～10)hc取浅孔40m、中孔50m4、直线段坡度与孔身底部坡度一致5、挑射角θ=20o1.2.2导墙尺寸1、导墙厚度一般为0.5～2m,本设计取1m。2、坝面高速水流自掺气断面平均掺气浓度CC=0.538(Ae−0.02)式中Ae=nV/R2/3其中n为溢流面曼宁糙率V为不计掺气时的断面平均流速R为不计掺气时的坎顶平均水深h掺气水流总深度ha=h/(1−c)对浅孔：Ho=186.34-118=68.34mV=φ(2gHo)1/2=0.95×(2×9.81×68.34)1/2=31.786m/sR=h=5.352mAe=nV/R2/3=0.012×31.786/5.3522/3=0.1364C=0.538(Ae-0.02)=0.538×(0.1364-0.02)=0.0626ha=h/(1-c)=5.352/(1-0.0626)=5.709m对中孔：R=h=6.082mAe=nV/R2/3=0.012×31.786/6.0822/3=0.1253C=0.538(Ae-0.02)=0.538×(0.1253-0.02)=0.05664ha=h/(1-c)=6.082/(1-0.05664)=6.447m考虑相关工程规范为保证特殊情况仍能运行要求增加的安全超高导墙分别取为7m、8m。1.3消能与防冲1.3.1水舌挑距L=式中：L——水舌挑距，是鼻坎末端至冲坑最深点的水平距离V1——坎顶水面流速α——鼻坎的挑射角度h1——坎顶垂直方向的水深h2——坎顶至河床表面落差对浅孔：H0=186.34-118=68.34mV1=1.1φ(2gH0)1/2=1.1×0.95×(2×9.8×68.34)1/2=38.25m/s（H0为水库水位至坎顶的落差）h1=hcosα=5.352×cos20o=5.029m(h为坎顶平均水深)h2=118-92=26m L=1/9.81×{38.252×sin20o×cos20o+38.25×cos20o×［38.252×sin220o+2×9.81×(5.029+26)］1/2}=150.26m对中孔：h1=hcosα=6.082×cos20o=5.715mL=151.14m水舌挑距计算得浅孔150.26m中孔151.14m1.3.2冲刷坑深度tr=krq0.5H0.25-t式中H——上下游水位差（m）tr——最大冲坑深度，由河床面算至坑底（m）kr——冲坑系数，取为1.0q——泄水建筑物出口断面的单宽流量（m3/s）对浅孔：q=178.651m3/sH=186.34-113.78=72.56mt=113.78-92=21.78mtk=αq0.5H0.25-t=1.0×178.6510.5×72.560.25-21.78=17.23mL/tk=150.26/17.23=8.721>2.5对中孔：q=202.143m3/stk=αq0.5H0.25-t=1.0×202.1430.5×72.560.25-21.78=19.72mL/tk=151.14/19.72=7.664>2.5都满足要求1.3.3消能率计算对冲消能主要为对冲点处水舌相撞损失动能。令m1=ρq1，m2=ρq2，ρ为水的密度。对x，y，z三个方向计算碰撞体动能损失：△Tx=ρ/2×q1q2/(q1+q2)×(V1cosα1sinθ1+V2cosα2sinθ2)2△Ty=ρ/2×q1q2/(q1+q2)×(V1cosα1cosθ1-V2cosα22)2△Tz=ρ/2×q1q2/(q1+q2)×(gt1-V1sinα1-gt2+V2sinα2)2△T=△Tx+△Ty+△TzT=ρ/2×(q1V12+q2V22)交汇点处的消能率η=△T/T对浅孔：q=178.651m3/sθ=45o△Tx=ρ×178.651×(31.786×cos20osin45o)2=95445.636ρT=ρqV2=ρ×178.651×31.7862=216179.465ρη=△T/T=95545.636/21617.465=41.15%对中孔：q=202.143m3/sθ=39o△Tx=ρ×202.143×(31.786×cos20osin39o)2=85542.696ρT=ρqV2=ρ×202.143×31.7862=244606.330ρη=△T/T=89283.577/244606.330=31.97%计算得：浅孔η=41.15%；中孔η=31.97%。1.4泄水孔口应力及配筋计算表3-17正常水位+温降时孔口处坝体应力及内水压力孔宽b梁向应力拱向应力内水压力(m)Py(MPa)Px(MPa)P（MPa）浅孔进口9.50.43482.09600.1915浅孔出口9.51.15221.53990.2910中孔进口7.50.18561.51110.4806中孔出口7.52.10031.61060.5297表3-18孔口应力计算结果表（单位：MPa）ρ角度10.950.90.850.80.750.70.650.60.550.5中孔进口0°-1.30-0.91-0.54-0.220.040.250.440.510.540.550.5345°16.027.411.473.112.462.151.981.661.421.291.1990°2.442.432.362.702.742.862.582.382.532.402.27中孔出口0°2.112.342.483.033.273.563.323.133.413.313.1645°12.645.503.302.402.071.922.041.851.691.621.5590°9.853.982.281.661.471.421.571.671.381.351.29浅孔进口0°-1.32-0.91-0.52-0.220.100.350.520.610.770.800.8045°15.097.241.553.853.162.722.311.982.041.911.8090°3.383.293.132.972.972.943.313.162.842.572.46浅孔出口0°0.510.770.981.151.331.461