YZ(桩号)= ZY(桩号) + L = (K7+258.85) + 471.24= K7+730.09
J = (K7+494.47)+ 11.06/2= K7+500 = JD(桩号) 23.某山岭区二级公路,边坡点桩号为K5+030,高程为427.68,两相邻纵坡度分别为i1=5%,i2=-4%,竖曲线半径为R=2000米,计算竖曲线诸要素及桩号为K5+000和K5+100处的设计高程。 解:(1)竖曲线要素
ω= i2- i1 = -4%-5% = -9% 该竖曲线为凸性 L=Rω= 2000* 0.09= 180m T= L/2=90m
E= T2/2R = 902/(2*2000)= 2.03m 竖曲线起点桩号为:(K5+030) - T = K4+940
竖曲线起点高程为:427.68 - T* i1 = 427.68 - 90* 5% = 423.18m
(2) K5+000 处
横距 x1 = (K5+000)- (K4+940)=60m 竖距 h1 = x12/2R= 602 / ( 2*2000)= 0.9m 切线高程= 423.18 + 60*5% = 426.18m 设计高程= 426.18 – 0.9 = 425.28m K5+100处
横距 x2 = (K5+100)- (K4+940)=160m 竖距 h2 = x22/2R= 1602 / ( 2*2000)= 6.4m 切线高程= 423.18 + 160*5% = 431.18m 设计高程= 431.18 – 6.4 = 424.78m
4. 已知两相邻平曲线:JD1桩号为K9+977.54,切线长T1=65.42 m,缓和曲线长Ls=35米,切曲差J=1.25m;JD2桩号为K10+182.69,切线长T2=45.83m。 计算:(1)JD1平曲线五个主点桩桩号;
(2)JD1—JD2交点间的距离;
(3)两曲线间的直线长度为多少。
解:(1)JD1处曲线长L1= 2T1-J = 2*65.42-1.25 = 129.59m 圆曲线长度LY1 = L- 2Ls = 129.59-35*2= 59.59m
则:ZH(桩号)= JD1(桩号) – T1 = (K9+977.54)- 65.42 = K9+912.12 HY(桩号)= ZH(桩号)+ Ls = (K9+912.12)+ 35 = K9+947.12
LY1QZ(桩号)= HY (桩号) + 2 = (K9+947.12) +59.59/2= K9+976.92
LY1YH (桩号)= QZ(桩号) + 2=(K9+976.92) + 59.59/2 = K10+006.71
检验式:QZ(桩号) +
HZ(桩号)= YH(桩号) + Ls = (K10+006.71) + 35= K10+041.71
J检验式:QZ(桩号) + 2 = (K9+976.92)+ 1.25/2 = K9+977.54 = JD1(桩号) (2) 设JD1—JD2交点间的距离 为l,
由JD2(桩号) = JD1(桩号) - T1 + L1 + (l - T1) 可知 l = JD2(桩号) - JD1(桩号) + 2* T1 - L1
= (K10+182.69) - (K9+977.54) + 2*65.42 – 129.59 = 206.40m
(3)两曲线间的直线长度为:l - T1 – T2 = 206.40- 65.42 – 45.83 = 95.15m
5.某级公路i1=2%,i2=5%,变坡点桩号:K6+500,变坡点设计高程为90.50m,竖曲线半经R=8000m。
计算:(1)计算竖曲线要素;
(2)竖曲线起终点桩号及标高; (3)计算桩号K6+580处的设计标高?
解: (1)竖曲线要素
ω= i2- i1 = 5%-2% = 3% 该竖曲线为凹性 L=Rω= 8000* 0.03= 240m T= L/2=120m
E= T2/2R = 1202/(2*8000)= 0.9m (2)竖曲线起点桩号为:(K6+500) - T = K6+380
竖曲线起点标高为:90.50 - T* i1 = 90.50 - 120* 2% = 88.10m (3)K6+580 处
横距 x = (K6+580)- (K6+380)= 200m 竖距 h1 = x2/2R= 2002 / ( 2*8000)= 2.5m 切线高程= 88.10 +200*2% = 92.10m 设计高程=92.10 +2.5 = 94.60m
6.已知某单圆曲线JD(交点)桩号为K2+100,圆曲线半径R=180m,转角α=30度, 计算圆曲线要素和各主点桩号? 解:(1)曲线要素 T= RtanL= R??2?180?tan30?=48.23m 2?180??180?30???180?=94.25m
E=R(sec?2?1)?180?(sec30??1)=6.35m 2J=2T-L=2.21m (2)计算主点桩号
ZY(桩号)= JD(桩号) – T =( K2+100)- 48.23 = K2+051.77 QZ(桩号)= ZY(桩号) +
L = (K2+051.77) + 94.25/2= K2+098.90 2YZ(桩号)= ZY(桩号) + L = (K2+051.77) + 94.25= K2+146.02 检验式:QZ(桩号) +
J = (K2+098.90)+ 2.21/2= K2+100= JD(桩号),计算正确 2
7.进行某山岭区三级公路纵断面设计,变坡点里程K5+590,其高程为499.81m,其中i1=0.05,i2=-0.03 ,变坡点处的竖曲线设计标高要求为497.85m。 试(1)确定该竖曲线半径及竖曲线要素。(12分) (2)计算K5+600处路基设计标高(3分) 解:解: (1)竖曲线半径及竖曲线要素
ω= i2- i1 = -0.03-0.05 = -0.08 该竖曲线为凸性 由题可知,该竖曲线的外距E= 499.81- 497.85 = 1.96m
由E= Rω2/8 可得,R = 8E/ω2 = 8*1.96/(0.08)2 = 2450m,则 L=Rω=2450* 0.08= 196m T= L/2=98m
(2)竖曲线起点桩号为:(K5+590) - T = K5+492
竖曲线起点标高为:499.81 - T* i1 = 499.81 - 98* 0.05 =494.91m K5+600 处
横距 x = (K5+600)- (K5+492)= 108m 竖距 h1 = x2/2R= 1082 / ( 2*2450)= 2.38m 切线高程= 494.91 + 108*0.05 = 500.31m 设计高程=500.38 – 2.38 = 497.93m
8.如图2所示,某转坡点处相邻两纵坡为i1=-5%(下坡)和i2=3%(上坡),转坡点桩号为
K3+700,转坡点设计标高为456.321m。设已知竖曲线外距E=1.5m,试据此计算:(1)竖曲线的半径R、长度L和切线长T;(2)竖曲线的起、终点桩号和设计标高;(3)桩号K3+660和K3+730处的设计标高。(10分)
解: (1)竖曲线要素
ω= i2- i1 = 3%-(-5%) = 8% 该竖曲线为凹性
由E= Rω2/8 可得,R = 8E/ω2 = 8*1.5/(0.08)2 =1875m,则 L=Rω=1875* 0.08= 150m T= L/2=75m
(2)竖曲线起点桩号为:(K3+700) - T = K3+625
竖曲线起点标高为:456.321 + T* i1 = 456.321 + 75* 5% = 460.071m 竖曲线终点桩号为:(K3+700) + T = K3+775
竖曲线终点标高为:456.321 + T* i2 = 456.321 + 75* 3% = 458.571m
(3)K3+660 处
横距 x1 = (K3+660)- (K3+625)=35m 竖距 h1 = x12/2R=352 / ( 2*1875)= 0.33m 切线高程= 460.071-35*5% =458.321m 设计高程=458.321 +0.33 = 458.651m
K3+730 处
横距 x2 = (K3+730)- (K3+625)=105m 竖距 h1 = x12/2R=1052 / ( 2*1875)= 2.94m 切线高程= 460.071-105*5% =454.821m 设计高程=454.821 +2.94 = 457.761m 9.道路某平面弯道,交点桩号为K11+765.43,转角αy=23°50′,圆曲线半径设计为450m,缓和曲线设计为100m,试按照以下次序完成平曲线计算。 (1)计算几何要素:β、ΔR、q
(2)计算平曲线要素:Th、Lh、Eh、Dh
(3)计算五个基本桩号(ZH、HY、QZ、YH、HZ) 解:(1)几何要素
L?100180?
???6.37?β=s?2R180?2?450?Ls2Ls410021004????0.93m △R=
24R2384R324?4502384?4503LsLs31001003???47.94m q==2240R22240?4502(2)平曲线要素
23?50?切线长Th=(R+△R)tan+q = (450+47.94)* tan ?47.94?153.01m
22'曲线长Lh=
?180R(??2?)?2Ls?287.06m
圆曲线长Ly=Lh – 2Ls= 87.06 ? 外距Eh = (R+△R)sec?R?58.90m2
切曲差 Dh = 2Th - Lh= 2*153.01-287.06 = 18.96m (3)计算主点桩号
ZH(桩号)= JD(桩号) - Th = (K11+765.43)- 153.01 = K11+612.42 HY(桩号)= ZH(桩号) + Ls=(K11+612.42)+ 100 = K11+712.42
QZ(桩号)= ZH(桩号) + Lh/2 = (K11+612.42)+ 287.06/2= K11+755.95 YH (桩号)= QZ(桩号)+ Ly/2=(K11+755.95)+ 87.06/2 = K11+799.48 HZ(桩号)= YH(桩号) + Ls=(K11+799.48)+ 100 = K11+899.48
检验式:QZ(桩号) + Dh /2=(K11+755.95)+ 18.96/2 = K11+765.43 = JD(桩号) 故, 计算正确
10.某公路纵断面设计,在K12+180设计一变坡点,标高为20.88,该变坡点前后的设计坡度分别为i1=-3.5%,i2=1.8%,设计的竖曲线半径R=5000m,试计算变坡点的设计标高和K12+200处的设计标高。
解: (1)竖曲线要素
ω= i2- i1 = 1.8%-(-3.5%) = 5.3% 该竖曲线为凹性 L=Rω=5000* 5.3%= 265m T= L/2=132.5m E= T2/2R = 1.76
(2)竖曲线起点桩号为:(K12+180) - T = K12+047.5
竖曲线起点标高为:20.88 + T* i1 = 20.88 + 132.5* 3.5% = 25.52m 边坡点K12+180处
设计标高为:20.88+E=20.88+1.76=22.64m K12+200 处
横距 x = (K12+200)- (K12+047.5)=152.5m 竖距 h = x2/2R=152.52 / ( 2*5000)= 2.33m 切线高程=25.52-152.5*3.5% =20.18 m 设计高程=20.18 +2.33 = 22.51m
11.某公路纵断面有一变坡点,其桩号里程为K8+100,高程为290.6m,变坡点前后的纵坡 分别为i1=-3%,i2=4%,变坡点处的竖曲线半径取R=3000m,试计算: (1)竖曲线曲线长L、切线长T、外距E;
(2)分别计算竖曲线起、终点里程和设计标高; (3)计算K8+100、K8+150的设计高程。 解: (1)竖曲线要素
ω= i2- i1 = 4%-(-3%) = 7% 该竖曲线为凹性 L=Rω=3000* 7%= 210m T= L/2=105m E= T2/2R = 1.84
(2)竖曲线起点桩号为:(K8+100) - T = K7+ 995
竖曲线起点标高为:290.6 + T* i1 = 290.6 + 105* 3% = 293.75m 竖曲线终点桩号为:(K8+100) + T = K8+ 205
竖曲线终点标高为:290.6 + T* i2 = 290.6 + 105* 4% = 294.80m (3) 边坡点K8+100处
设计标高为:290.6+E=290.6+1.84=292.44m K8+150 处
横距 x = (K8+150)- (K7+ 995)=155m 竖距 h = x2/2R=1552 / ( 2*3000)= 4.00m 切线高程=293.75-155*3% =289.10 m 设计高程=289.10 +4.00 = 293.10m
12.某平原区二级公路,测量得JD1、JD2、JD3在JD2处的夹角为149°56′00″,并设JD2的桩号为K8+099.51,JD2的R设计为200m,试计算JD2的圆曲线元素及主点里程。
παR180αα参考公式: T=RtgE=R(sec-1)
22
J=2T-L
L=解:(1)曲线要素
‘149?56T= Rtan?200?tan=744.68m
22???200?149?56'?L= R?=523.09m 180?180??
E=R(sec?2?1)?200?(sec?2?1)=570.98m
J=2T-L=966.27m (2)计算JD3主点桩号
ZY(桩号)= JD(桩号) – T =( K8+099.51)- 744.68 = K7+354.83 QZ(桩号)= ZY(桩号) +
L = (K7+354.83) + 523.09/2= K7+616.38 2YZ(桩号)= ZY(桩号) + L = (K7+354.83) +523.09= K7+877.92 检验式:QZ(桩号) + 计算正确
J = (K7+616.38)+ 966.27/2= K8+099.51 = JD(桩号) 2