4多边形面积计算挡土墙压力计算.ppt

1,土压力计算,华东交通大学,教师：赵秀绍,2,第一个例题多边形的面积求解,3,1.1设计界面,有时路基是多边形的，要用平均断面法或平均距离法计算土石方量，就应用到多边形面积求解。,4,1.2计算原理,5,1.3加载多边形的角点数,Dimi%IfVal(Text2.Text)Text1.CountAndVal(Text2)Val(Text2)ThenFori=Text1.Count-1ToVal(Text2)Step-1UnloadLabel1(i)UnloadText1(i)NextElseIfVal(Text2)0Then加载土层数IfVal(Text16)Text14.CountThenFori=Text14.ubound+1ToVal(Text16)-1LoadText14(i)：LoadText15(i)LoadText17(i)：LoadLabel11(i)Text14(i).Top=Text14(i-1).Top+300Text15(i).Top=Text15(i-1).Top+300Text17(i).Top=Text17(i-1).Top+300Label11(i).Top=Label11(i-1).Top+300Text14(i).Visible=TrueText15(i).Visible=TrueText17(i).Visible=TrueLabel11(i).Visible=TrueLabel11(i).Caption=第&i+1&层Next,ElseIfVal(Text16)0ThenUnloadText14(i)UnloadText15(i)UnloadText17(i)UnloadLabel11(i)EndIfNextEndIfEndIfEndSub,11,2.3演示数据,PrivateSubCommand12_Click()Text16=3Text16_ChangeText13=10&kPaText14(0).Text=18Text14(1).Text=20Text14(2).Text=15Text15(0).Text=2Text15(1).Text=1.5Text15(2).Text=3EndSub,12,2.4计算过程,PrivateSubCommand10_Click()DimiAsInteger,PAsDouble,HAsSingleP=0:H=0P=P+Val(Text13)地面荷载Fori=0ToText14.uboundP=P+Val(Text14(i)*Val(Text15(i)H=H+Val(Text15(i)计算总厚度Text17(i)=Format(P,0.#kPa)显示计算结果Next,13,2.4计算过程画图过程,Picture2.ClsPicture2.Scale(-10,-0.5)-(P+20,H+3)Picture2.Line(0,0)-(0,H+3)Picture2.Line(0,0)-(P+20,0)H=0画坐标轴,Fori=0ToText14.uboundIfi=0Then就是最顶上的情况Picture2.Line(0,0)-(Val(Text13),0)Picture2.PrintText13.TextPicture2.Line(Val(Text13),0)-(Val(Text17(0),Val(Text15(0)Picture2.Line(0,Val(Text15(0)-(Val(Text17(0),Val(Text15(0)Picture2.PrintFormat(Val(Text17(0),0.#kPa)H=H+Val(Text15(0),ElsePicture2.Line(Val(Text17(i-1),H)-(Val(Text17(i),H+Val(Text15(i)Picture2.PrintFormat(Val(Text17(i),0.#kPa)正常情况Picture2.Line(0,H+Val(Text15(i)-(Val(Text17(i),H+Val(Text15(i)H=H+Val(Text15(i)EndIfNextEndSub,14,2.5运行界面,15,第三个例题静止土压力求解,16,3.1静止土压力系数取值,对于侧限应力状态：p0=sh=K0sv=u/(1-u)sv=u/(1-u)gzK0=n/(1-n)由于土的n很难确定，K0常用经验公式计算对于砂土、正常固结粘土：K01-sinf超固结粘性土：,17,静止土压力系数取值,公路桥涵设计通用规范给出了静止土压力系数的参考值为：砾石、卵石：0.20砂土：0.25亚砂土：0.35亚粘性土：0.45粘土：0.55,18,3.2设计界面,19,3.3地层数的确定,PrivateSubText11_Change()IfVal(Text11)0Then加载土层数IfVal(Text11)Text7.CountThenFori=Text7.ubound+1ToVal(Text11)-1LoadText7(i):LoadText8(i):LoadText10(i)Text7(i).Top=Text7(i-1).Top+300Text8(i).Top=Text8(i-1).Top+300Text10(i).Top=Text10(i-1).Top+300Text7(i).Visible=True：Text8(i).Visible=True：Text10(i).Visible=TrueNext,ElseIfVal(Text11)0ThenUnloadText7(i):UnloadText8(i):UnloadText10(i)EndIfNextEndIfEndIfEndSub,20,3.4演示数据,PrivateSubCommand6_Click()Text11=3Command8_ClickText7(0)=1：Text8(0)=20：Text7(1)=1Text8(1)=16：Text7(2)=1.5：Text8(2)=18Option2(4).Value=TrueOption2_Click4EndSub,21,3.5静止土压力系数求解,PrivateSubOption2_Click(IndexAsInteger)OnErrorResumeNextDimtmpAsDoubleK0=0SelectCaseIndexCase0IfText6(0)=OrVal(Text6(0)0.5ThenK0=0EndIf。省略，其它与此同,IfK0=0ThenText12=出错ElseText12=K0EndIf,22,3.5输入数字的响应,PrivateSubText6_Change(IndexAsInteger)Dimi%i=IndexIfi=4Theni=3Option2_ClickiOption2(i).Value=TrueEndSub,当输入数字时，相应的单选按扭被选中,23,3.6具体运算过程,PrivateSubCommand7_Click()DimE0AsDouble,P0()AsDoubleDimH()AsDouble,y()AsDoubleReDimH(Val(Text11)-1),y(Val(Text11)-1),P0(Val(Text11)-1)DimiAsInteger定义动态数组，贮存相关值,Fori=0ToVal(Text11)-1H(i)=Val(Text7(i)y(i)=Val(Text8(i)Ifi0ThenP0(i)=P0(i-1)+K0*H(i)*y(i)正常累加ElseP0(i)=K0*H(i)*y(i)最上层情况EndIfText10(i)=Format(P0(i),0.000kPa)输出每层的土压力Next,每一层土压力计算,24,3.6具体运算过程,计算合力大小E0=0Fori=0ToVal(Text11)-1Ifi=0ThenE0=E0+0.5*Val(Text7(i)*Val(Text10(i)ElseE0=E0+0.5*Val(Text7(i)*(Val(Text10(i)+Val(Text10(i-1)EndIfNextText9(1)=Format(E0,0.000kN/m)输出合力,25,3.7计算合力作用点,DimxAsSingle,AAsSinglex=0：A=0力矩Fori=0ToVal(Text11)-1Ifi=0Thenx=x+0.5*Val(Text10(i)*Val(Text7(i)*2/3*Val(Text7(i)绕顶点的力矩A=A+Val(Text7(i)作用距离Elsex=x+Val(Text10(i-1)*Val(Text7(i)*(0.5*Val(Text7(i)+A)矩形产生的力矩,x=x+0.5*(Val(Text10(i)-Val(Text10(i-1)*Val(Text7(i)*(2/3*Val(Text7(i)+A)三角形产生的力矩A=A+Val(Text7(i)EndIfNextix=x/Val(Text9(1)作用点距顶端的距离A=0Fori=0ToVal(Text11)-1A=A+Val(Text7(i)Nextx=A-x算出距最底端的距离Text9(2)=Format(x,0.000m),26,3.8绘图方法的实现,Picture1.ClsPicture1.Scale(0,0)-(Val(Text10(Val(Text11)-1)+2,A+1)A=0Fori=0ToVal(Text11)-1Ifi=0ThenA=A+Val(Text7(i)Picture1.Line(0,0)-(Val(Text10(i),A)斜线Picture1.Line(0,A)-(Val(Text10(i),A)横线Picture1.PrintVal(Text10(i)显示土压力,Picture1.CurrentX=Val(Text10(