长安大学路基路面课程设计报告双语

1、.Course ProjectRoad Pavement Engineering Highway School of Changan University *X Advisor: *X 2016-*-*. v.Part I Data CollectionThe project is segment A of Shijiazhuang to Zhengzhou grade 1 highway. 1.1 Climate dataNatural Zone: II4Annual Rainfall: 570mm; HT: 37C; LT: -7C Frost-thaw: Max frozen depth

2、 of 60cm; Frozen index of 1023C on average and 1540C in Max 1.2 Geological and subgrade conditionsSoil Type: alluvial soil(as clay soils of low liquid limit) Embankment: 0.6m of height ；Water table: 2.7m from the roadbed surface in mid-wet state；Subgrade width: 24.5m=4*3.75+2*2.5(Hard shoulder)+2*0.

3、75(soil shoulder)+3.0(central median) 1.3 Traffic dataTable 1. Traffic combinationNO.ClassificationVehicle modelsDaily traffic flow(veh/d)Vehicle conversion coefficient1Medium sizeMitsubishi T653B 3201.52Medium sizeJieFang CA390 2201.53Large sizeJAC HF15018024Large sizeCNHTC JN16223025TrailerXJ HQP4

4、014036TrailerDFM EQ155903Note: NO. 5 & 6 is vision traffic, only considered in the calculation of the pavement structure.PartII Asphalt Pavement Design1.1 Traffic AnalysisESALs calculation Specific calculating process is in excel, and applied equations are:Deflection and asphalt layer bottom ten

5、sile stress as design criteria Tensile stress at the bottom of semi-rigid base as design criteria Accumulative equivalent ESALsIncreasing ratio for every five years are1=8%,2=7%, 3=5% so the total increasing ratio G can be calculated as:G1= (1+8%)5-1/ 8%=5.87 G2= (1+8%)5*(1+7%)5-1/ 7%=8.45G3= (1+8%)

6、5*(1+7%)5*(1+5%)5-1/ 5%=11.39G=G1+G2+G2=25.71According to specification for design of highway asphalt pavement clause 3.1.7, Ne= Ne1 =365*8534*25.71*0.5=40.04msa(Deflection and asphalt layer bottom tensile stress as design criteria)Ne2=365*82980*25.71*0.5=389.3msa(Tensile stress at the bottom of sem

7、i-rigid base as design criteria)1.2Subgrade ModulusFrom the table 5.1.4-1 in JTG D50-2006, consistency is between 0.95-1.10, the corresponding MR is less than 40 MPa and for extremely heavy traffic subgrade MRmin=40MPa, so MR=40MPa.2. Combination Design2.1 Asphalt surface course & Base and subba

8、se coursesAsphalt surface and Base and subbase material and thickness selection limit is from the table below in JTG D50-2006:2.2 SummaryThree combination schemes areScheme1: (Asphalt + asphalt + granular )4cmAC13+5cmAC16+7cmAC25+20cmAM20+30cm graded macadamScheme2 : (Asphalt + HBM + Granular) 5cmAC

9、10+7cmAC16+10cmSMA20+30cm cement stabilized base+15cm graded macadam Scheme3:(Asphalt + Asphalt + HBM)4cmAC10+7cmAC16+18cmSMA20+30cm limestone soilAnd choose scheme2 to check whether it meets requirement.3. Material proportion properties3.1 Asphalt surface MaterialsThe corresponding material propert

10、ies can be found in the Table E.1& 2:Namely:typeEC(20C)MPaEC(15C)PMaSplitting strength(MPa)AC10150021001.5AC16130018000.93.2 Base and subbase materialsTypeEC(deflection)MPaEC (tensile stress)PMaSplitting strength(PMa)Cement macadam160040000.55SMA150019000.8Graded macadam450-4. Thickness Design4.

11、1 Determine design criteriaDetermine Design Deflection Ld:Equation givenAC=1(1 for expressway & class I, 1.1 for class II, and 1.2 for others) AS=1(1 for AC and 1.1 for others)Ab=1(1 for semi-rigid base, and 1.6 for flexible base)So Ld =600*4004*104*1*1*1=18.1(0.01mm)Determine Tensile Stress at

12、bottom of each layerEquation given AC10 layer: Ks=0.09Ne0.22/Ac=0.09*400400000.22/1=4.23 , R=sp/ks=1.5/4.23=0.36MPaAC16layer:Ks=0.09Ne0.22/Ac=0.09*400400000.22/1=4.23 , R=sp/ks=0.9/4.23=0.21MPaSMA20layer:Ks=0.09Ne0.22/Ac=0.09*400400000.22/1=0.55 , R=sp/ks=0.9/4.23=0.21MPaCement stabilized base layer

13、:Ks=0.35Ne0.22/Ac=0.35*400400000.22/1=16.47 R=sp/ks=0.55/16.47=0.03MPa4.2 Determine calculated criteriaBISAR Solution for surface resilient deflection：BISAR Solution for layer bottom tensile stresses Layer1Layer2Layer3Layer44.3 Finalize the thickness designCompare the design criteria and the calcula

14、ted criteria:Correction of BISAR solution for deflection:Assuming ls=ld=18.1(0.01mm), then F=1.63*(18.1/(2000*10.65)0.38* (40/0.7)0.36=0.476 Therefore, corrected BISAR solution is Ls=33.03*0.476= 15.72(0.01mm) <Ld=18.1mmThe scheme *2 meets the requirement of deflection.And layer bottom tensile st

15、resses:layerCalculated tensile stress(MPa)Allowable tensile stress(MPa)10.0460.3620.0590.2130.0240.2140.025(compression)0.03So calculated tensile stress meets requirement.5. Finalize the designFrost-thaw check :Max frozen depth is 60cm and moderate wet subgrade, so maximum value of minimum anti-free

16、zing thickness is 40cm according to Table below:and pavement thickness is 5+7+10+30+15=67cm>40cm, there is no need to set another layer.Finial thickness design of scheme2:Part III Cement Concrete Pavement Design1. Project StatementNatural Zone II4Pavt width: 7mSubgrade soil: clay with a low liqui

17、d limitWater table: 1.2m beneath the roadbed surfaceAggregate: ganitePav't type: JPCPPs=80KN, Pm=150KNADTT=4500saAnnual increasing rate: 5%2. Design data2.1 Traffic AnalysisWheel-track coefficient:Design period: 20ys, and Safety level: class-II, pav't width=7m, according to JTG D40-2011 figu

18、re=0.62, so accumulative equivalent ESALs can be calculated as:Ne=NS×（1+gr)t-1×365×/gr=4500×(80/100)16×(1+5%)20-1×365×0.62/5%=947803saNe is between 0.03msa1msa belonging to moderate traffic level.2.2 Subgrade ModulusAccording to JTG D40-2011 appendix E, reference M

19、R=90MPaAnd Humid coefficient= 0.75So MR=90*0.75=67.5MPa3. Combination Design3.1 Concrete Surface courseAccording to JTG D40-2011, concrete slab recommended thickness select 240mm3.2 Base and subbase coursesAccording to JTG D40-2011, available materials for base areLight or ModerateGraded Crushed Sto

20、nesCement-stabilized, lime-ash-stabilized crushed stonesAnd available materials for subbase areLight or ModerateUnscreened crushed stones, graded crushed stones, or no subbaseConstruction thicknessGraded Crushed stones/ Unscreened crushed stones or gravels100-200Therefore, 200mm graded crushed stone

21、s as base layer and no subbase.3.3 SummaryLayerMaterialThickness(mm)SurfacePPC230SubaseGraded crushed stones2003.4 Other design parameterReliability : for class II highway, safety level is II and target reliability is 85 percent, reliability index is 1.04.And from table below the variance level is m

22、oderate, so reliability coefficient is 1.13.Temperature Gradient is 88 C/m based on table below.4. Joint Design4.1 Transverse JointsTransverse Joint spacing: 4.5m and no dowel bars are used at the transverse joints 4.2 Longitudinal JointsLongitudinal joint spacing: 3.5m and tie bars are used at the

23、longitudinal joints. Besides, the size of tie bar is 14*700*600 based on table below from JTG D40-2011.5. Material proportion properties5.1 Concrete MaterialsRupture strength is 4.5MPa, MR=29GPa, Poissons ratio is 0.15, Thermal coefficient is 1E-5Traffic classPlain Cement Concete (PCC)Moderate>=4

24、.55.2 Base and subbase materialsMR=300MPa based on JTG D40-2011 appendix E6. Calculation and analysis of load-induced stress6.1 Load-induced fatigue stress Because concrete slab on granular base can be considered as single-layer plate system on elastic foundation, so the equation for Load-induced fa

25、tigue stress is Kr=0.87 (0.870.92, tire bar) Kc=1.05(checked in table as follow) Kf= Ne =(94.78×104)0.057=2.191And in ,Equivalent modulus of unbound materials: Et=130Mpa Ex= (hi2Ei)/ hi2=h12E1/h12=300MPa Hx= hi=h1=0.20m =0.86+0.26ln( hx )=0.86+0.26×ln(0.20）=0.442 Et=(Ex/E0)E0=(300/67.5)0.4

26、42×67.5=130.51MPaBending stiffness: 34.17MN·m Dc=Echc3/(12(1-vc2)）=29000×0.243/(12×(1-0.152）=34.17MN·mr=1.21× (Dc/ Et )1/3=0.775mso ps=1.47×10-3r0.70hc-2Ps0.94=1.47×10-3×0.7750.70×0.24-2×800.94=1.313MPaThus pr= kc×kr×kf×ps =1.05×2.191×0.87×1.313=2.627MPa6.2 Load-induced ultimate stresspm=1.47×10-3r0.70hc-2Pm0.94=1.47×10-3×0.7750.70×0.24-2×1500.94=2.541MPap,max=kr×kc×pm=0.87×1.05×2.37