扶壁式挡土墙计算书项目名称_____________日期_____________设计者_____________校对者_____________一、示意图:二、基本资料:1.依据规范及参考书目:《水工挡土墙设计规范》(SL379-2007),以下简称《规范》《水工混凝土结构设计规范》(SL 191-2008),以下简称《砼规》《水工建筑物荷载设计规范》(DL 5077-1997)《建筑结构静力计算手册》(第二版)《水工挡土墙设计》(中国水利水电出版社)2.断面尺寸参数:墙顶宽度B1 = 0.60m,墙面上部高度H = 25.00m墙面变厚B5 = 0.00m,墙背变厚B6 = 0.00m前趾宽度B2 = 2.10m,后踵宽度B3 = 13.30m前趾端部高度H2 = 1.00m,前趾根部高度H3 = 1.80m后踵板高度H1 = 1.80m,墙前填土高度H4 = 1.80m扶臂厚度b = 1.00m,扶臂顶部宽度B4 = 1.00m扶臂数量n = 3个,扶臂净距L = 6.00m墙面板左挑L1 = 2.46m,墙面板左挑L2 = 2.46m3.设计参数:挡土墙的建筑物级别为2级,荷载组合为基本组合。
抗震类型:非抗震区挡土墙。
水上回填土内摩擦角φ= 40.00度,水下回填土内摩擦角φ' = 40.00度回填土凝聚力C = 0.00kN/m2,墙底与地基间摩擦系数f = 0.60基础为非岩石地基。
填土面与水平面夹角β= 10.00度,回填土顶面均布荷载q = 0.00kN/m地下水位距墙底高h1 = 0.00m,墙前水深(墙底算起)h2 = 0.00m回填土湿容重γ1 = 21.00kN/m3,回填土浮容重γ2 = 10.00kN/m3混凝土强度等级:C25受力钢筋强度等级:二级,保护层厚度as = 0.050 m扶臂箍筋强度等级:二级地基允许承载力[σo] = 1000.00 kPa三、计算过程:1.计算公式:郎肯土压力计算公式如下:E =0.5×γ×H2×K aE x=E×cos(β)E y=E×sin(β)K a=cosβ×[cosβ-(cos2β-cos2φ)1/2]/[cosβ+(cos2β-cos2φ)1/2] (《规范》式A.0.1-3)式中:E为作用于墙背的土压力,作用点为距墙底1/3高处,方向与水平面成β夹角K a为土压力系数程序算得土压力系数K a = 0.2252.总水平力、总竖向力及各力对前趾力矩计算:单位:水平力、竖向力为kN;力臂为m;弯矩为kN·m。
所有垂直荷载之和∑G=8754.22kN所有水平荷载之和∑F H=1967.21kN所有对墙前趾的稳定力矩之和∑M V=81392.76kN·m所有对墙前趾的倾覆力矩之和∑M H=-19300.41kN·m所有对墙前趾的力矩之和∑M=62092.35kN·m3.抗滑稳定验算:抗滑稳定安全系数计算公式为:Kc=f×∑G/∑F H从《规范》中表3.2.7查得,抗滑稳定安全系数[Kc]=1.30Kc=0.600×8754.218/1967.213=2.67Kc=2.67≥[Kc]=1.30,故抗滑稳定安全系数满足要求4.抗倾覆稳定验算:从《规范》中表3.2.12、3.2.13条查得,抗倾覆稳定安全系数[Ko]=1.50抗倾覆稳定安全系数计算公式为:Ko=∑M V/∑M HKo=81392.761/19300.412=4.22Ko=4.22≥[Ko]=1.50,故抗倾覆稳定安全系数满足要求5.地基承载力验算:地基承载力按《规范》中第6.3.1、6.3.2条进行校核。
基底应力计算公式为:P max=∑G / B ×(1 + 6 ×e / B)P min=∑G / B ×(1 - 6 ×e / B)偏心距e =B / 2 - ∑M / ∑G=16.00 / 2 - 62092.35 / 8754.22 = 0.907 mP max=8754.22/16.00×(1+6×0.907/16.00)=733.26 kPaP min=8754.22/16.00×(1-6×0.907/16.00)=361.01 kPaP max=733.26 ≤1.2[σo] =1.2×1000.00 =1200.00,满足要求。
(P min+P max)/2 =547.14 ≤[σo] =1000.00,满足要求η=P max/P min=733.26/361.01=2.03 > 2.0故地基承载力不满足要求!四、墙面板结构计算:1.计算依据:a、作用在墙面板上的荷载为三角形或梯形;b、在距底板高度1.5Lx范围内,按三面固定一面简支双向板计算内力;c、在距底板高度1.5Lx以上,水平方向取单宽截条按连续梁计算内力;d、截面按受弯构件进行配筋计算,公式如下:K×M ≤f c×b×χ×(ho-χ/2)+f y'×As'(ho-a s')《砼规》式6.2.1-1f c×b×χ≤f y×As - f y'×As' 《砼规》式6.2.1-22.内力计算:墙面板Lx = 6.00 m,Ly = 9.00 m,从静力计算手册查得:均布荷载作用下,墙面板弯矩系数为:K x = 0.0384,K y = 0.0113, K x o = -0.0794K y o = -0.0569,K ox = 0.0433,K xz o = -0.0616三角形荷载作用下,墙面板弯矩系数为:K'x = 0.0184,K'y = 0.0071,K'x o = -0.0387K'y o = -0.0421,K'ox = 0.0065,K'xz o = -0.0015面板梯形荷载大值为q = 117.97kN,小值q' = 75.50kN将均布荷载q1 = 75.50kN/m与三角形荷载q2= 0.00kN/m产生的弯矩叠加得:M x = K x×q1×L x2 + K'x×q2×L x2= 0.0384×75.50×6.002 + 0.0184×42.47×6.002 = 132.50 kN·mM y = K y×q1×L x2 + K'y×q2×Lx2= 0.0113×75.50×6.002 + 0.0071×42.47×6.002 = 41.57 kN·mMxo = Kxo×q1×Lx2 + K'xo×q2×Lx2= -0.0794×75.50×6.002 + (-0.0387)×42.47×6.002 = -274.98 kN·mMyo = Kyo×q1×Lx2 + K'yo×q2×Lx2= -0.0569×75.50×6.002 + (-0.0421)×42.47×6.002 = -219.02 kN·m Mox = Kox×q1×Lx2 + K'ox×q2×Lx2= 0.0433×75.50×6.002 + (0.0065)×42.47×6.002 = 127.63 kN·m Mxzo = Kxzo×q1×Lx2 + K'xzo×q2×Lx2= -0.0616×75.50×6.002 + (-0.0015)×42.47×6.002 = -169.72 kN·m 3.纵向支座(负弯矩)强度及配筋计算:截面高度h = 600 mm,弯矩M = -274.98 kN·m钢筋计算面积As' = 2101mm2,实配As = 2244mm2(D20@140)抗裂验算不满足要求,裂缝宽度δmax = 0.314 mm4.纵向跨中(正弯矩)强度及配筋计算:截面高度h = 600 mm,弯矩M = 132.50 kN·m钢筋计算面积As' = 986mm2,实配As = 1058mm2(D16@190)抗裂验算满足要求,裂缝宽度δmax = 0.300 mm5.竖向支座(负弯矩)强度及配筋计算:截面高度h = 600 mm,弯矩M = -219.02 kN·m钢筋计算面积As' = 1656mm2,实配As = 1745mm2(D20@180)抗裂验算不满足要求,裂缝宽度δmax = 0.321 mm6.竖向跨中(正弯矩)强度及配筋计算:截面高度h = 600 mm,弯矩M = 41.57 kN·m钢筋计算面积As' = 825mm2,实配As = 874mm2(D16@230)抗裂验算满足要求,裂缝宽度δmax = 0.114 mm五、前趾根部截面承载力验算及配筋计算:1.计算依据:截面按受弯构件进行承载力和配筋计算:K×M ≤fc×b×χ×(ho-χ/2)+fy'×As'(ho-as')《砼规》式6.2.1-1fc×b×χ≤fy×As - fy'×As' 《砼规》式6.2.1-22.总水平力、总竖向力及各力对截面弯矩计算:单位:水平力、竖向力为kN;力臂为m;弯矩为kN·m。
3.截面配筋及裂缝宽度计算结果:截面高度h = 1800 mm,弯矩M = -1486.42 kN·m钢筋计算面积As' = 3485mm2,实配As = 3491mm2(D20@90)抗裂验算不满足要求,裂缝宽度δmax = 0.323 mm六、踵板结构计算:1.计算依据和假定:a、将作用在踵板上的荷载转化为三角形或梯形;b、在距墙面板1.5Lx范围内,按三面固定一面简支双向板计算内力;c、在距墙面板1.5Lx以外,纵向取单宽截条按连续梁计算内力;d、截面按受弯构件进行配筋计算,公式如下:K×M ≤fc×b×χ×(ho-χ/2)+fy'×As'(ho-as')《砼规》式6.2.1-1fc×b×χ≤fy×As - fy'×As' 《砼规》式6.2.1-22.作用在踵板上的荷载计算:内侧土重W1' = 525.00 kN;外侧土重W1 = 574.25 kN踵板自重W2 = 525.00×574 = 0.00 kN作用在踵板上侧土压力产生的竖向荷载W3 = EB×sin(β)/B3= 289.64×sin(10.0°)/13.30 = 3.78 kN作用在踵板端部土压力产生的竖向荷载W4 = 2Eh×sin(β)/B3= 2.0×239.91×sin(10.0°)/13.30 = 6.26 kN前趾弯矩产生的竖向荷载W5 = 2.4×M/B32= 2.4×-1486.42/13.302 = 20.17 kN内侧基底反力σ1 = 670.45 kN;外侧基底反力σ2 = 361.01 kN作用在踵板内侧总荷载∑W' = W1'+W2+W3+W6+W7-σ3-σ1= 525.00+45.00+3.78+0.00+0.00-0.00-670.45= -96.67 kN作用在踵板外侧总荷载∑W = W1+W2+W3+W4+W5+W6+W7-σ4-σ2= 574.25+45.00+3.78+6.26+20.17+0.00+0.00-0.00-361.01= 239.20 kN3.内力计算:踵板Lx = 6.00 m,Ly = 9.00 m,从静力计算手册查得:均布荷载作用下,墙面板弯矩系数为:Kx = 0.0384,Ky = 0.0113,Kxo = -0.0794Kyo = -0.0569,Kox = 0.0433,Kxzo = -0.0616三角形荷载作用下,墙面板弯矩系数为:K'x = 0.0184,K'y = 0.0071,K'xo = -0.0387K'yo = -0.0421,K'ox = 0.0065,K'xzo = -0.0015踵板梯形荷载小值为q = 0.00kN,大值q' = 130.61kN将均布荷载q1 = 130.61kN/m与三角形荷载q2= 0.00kN/m产生的弯矩叠加得:Mx = Kx×q1×Lx2 + K'x×q2×Lx2= 0.0384×130.61×6.002 + 0.0184×(-130.61)×6.002 = 94.04 kN·m My = Ky×q1×Lx2 + K'y×q2×Lx2= 0.0113×130.61×6.002 + 0.0071×(-130.61)×6.002 = 19.75 kN·m Mxo = Kxo×q1×Lx2 + K'xo×q2×Lx2= -0.0794×130.61×6.002 + (-0.0387)×(-130.61)×6.002 = -191.37 kN·m Myo = Kyo×q1×Lx2 + K'yo×q2×Lx2= -0.0569×130.61×6.002 + (-0.0421)×(-130.61)×6.002 = -69.59 kN·m Mox = Kox×q1×Lx2 + K'ox×q2×Lx2= 0.0433×130.61×6.002 + (0.0065)×(-130.61)×6.002 = 173.04 kN·m Mxzo = Kxzo×q1×Lx2 + K'xzo×q2×Lx2= -0.0616×130.61×6.002 + (-0.0015)×(-130.61)×6.002 = -282.59 kN·m在均布荷载q = 239.20 kN/m作用下,踵板端部纵向按连续梁计算得弯矩为:左支座弯矩Ml = -651.57 kN·m,跨中弯矩Mm = 470.58 kN·m右支座弯矩Mr = -560.08 kN·m4.纵向支座(负弯矩)强度及配筋计算:截面高度h = 1800 mm,弯矩M = -651.57 kN·m钢筋计算面积As' = 2625mm2,实配As = 2856mm2(D20@110)抗裂验算满足要求,裂缝宽度δmax = 0.184 mm5.纵向跨中(正弯矩)强度及配筋计算:截面高度h = 1800 mm,弯矩M = 470.58 kN·m钢筋计算面积As' = 2625mm2,实配As = 2872mm2(D16@70)抗裂验算满足要求,裂缝宽度δmax = 0.124 mm6.竖向支座(负弯矩)强度及配筋计算:截面高度h = 1800 mm,弯矩M = -219.02 kN·m钢筋计算面积As' = 2625mm2,实配As = 2856mm2(D20@110)抗裂验算满足要求,裂缝宽度δmax = 0.062 mm七、扶臂结构计算:1.计算依据和假定:a、扶臂与部分面板组成变截面的T形梁,按悬臂梁进行受弯结构计算;b、荷载为跨中到跨中作用在墙面板及扶臂上的水平土压力和水压力;c、截面按受弯构件进行配筋计算,公式如下:K×M ≤fc×b×χ×(ho-χ/2)+fy'×As'(ho-as')《砼规》式6.2.1-1fc×b×χ≤fy×As - fy'×As' 《砼规》式6.2.1-22.距挡土墙墙底高度H=1.80m水平截面强度及配筋计算:截面高度h = 13900 mm,截面宽度b = 1000 mm翼缘高度hf = 600 mm,翼缘宽度bf = 7000 mmT形截面所受弯矩M = 111632.97 kN·m钢筋计算面积As' = 33375mm2,实配As = 33379mm2(68D25)抗裂验算不满足要求,裂缝宽度δmax = 0.212 mm3.距挡土墙墙底高度H=10.13m水平截面强度及配筋计算:截面高度h = 9800 mm,截面宽度b = 1000 mm翼缘高度hf = 600 mm,翼缘宽度bf = 5000 mmT形截面所受弯矩M = 18133.97 kN·m钢筋计算面积As' = 14550mm2,实配As = 14726mm2(30D25)抗裂验算满足要求,裂缝宽度δmax = 0.121 mm4.距挡土墙墙底高度H=18.47m水平截面强度及配筋计算:截面高度h = 5700 mm,截面宽度b = 1000 mm翼缘高度hf = 600 mm,翼缘宽度bf = 3000 mmT形截面所受弯矩M = 1375.44 kN·m钢筋计算面积As' = 8400mm2,实配As = 8836mm2(18D25)抗裂验算满足要求,裂缝宽度δmax = 0.029 mm5.扶臂水平拉筋计算:水平拉筋承受的剪力Q = 0.5×117.97×6.00 = 353.91 kN水平拉筋计算面积Asv/s = K×Q/fy= 1.20×353.91/300.00 = 1.416 mm水平拉筋计算面积Asv'/s = 1.416 mm,实配Asv/s = 1.571 mm(2D10@100) 6.扶臂垂直拉筋计算:垂直拉筋承受的剪力Q = 239.20×6.00 = 1435.21 kN垂直拉筋计算面积Asv/s = K×Q/fy= 1.20×1435.21/300.00 = 5.741 mm垂直拉筋计算面积Asv'/s = 5.741 mm,实配Asv/s = 6.158 mm(2D14@50)。