长安大学路基路面课程设计(双语)

Course Project

Road Pavement Engineering

Highway School of Chang’an University

XXX

Advisor: XXX

2016-xx-xx

Part I Data Collection

The project is segment A of Shijiazhuang to Zhengzhou grade 1 highway.

1.1Climate data

Natural Zone: II4

Annual Rainfall: 570mm;

HT: 37C; LT: -7C

Frost-thaw: Max frozen depth of 60cm;

Frozen index of 1023C on average and 1540C in Max

1.2Geological and subgrade conditions

Soil 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*0.75(soil shoulder)+3.0(central median)

1.3Traffic data

Table 1. Traffic combination

Note: NO. 5 & 6 is vision traffic, only considered in the calculation of the pavement structure.

Part II Asphalt Pavement Design

1.1 Traffic Analysis

ESALs calculation

Specific calculating process is in excel, and applied equations are: Deflection and asphalt layer bottom tensile stress as design criteria

Tensile stress at the bottom of semi-rigid base as design criteria

Accumulative equivalent ESALs

Increasing ratio for every five years areγ1=8%,γ2=7%, γ3=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%=8.45

G3= (1+8%)5*(1+7%)5*[(1+5%)5-1]/ 5%=11.39

G=G1+G2+G2=25.71

According 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 semi-rigid base as design criteria) 1.2Subgrade Modulus

From 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 MR min=40MPa, so MR=40MPa.

2. Combination Design

2.1 Asphalt surface course & Base and subbase courses

Asphalt surface and Base and subbase material and thickness selection limit is from the table below in JTG D50-2006:

2.2 Summary

Three combination schemes are

Scheme1: (Asphalt + asphalt + granular )

4cmAC13+5cmAC16+7cmAC25+20cmAM20+30cm graded macadam

Scheme2 : (Asphalt + HBM + Granular)

5cmAC10+7cmAC16+10cmSMA20+30cm cement stabilized base+15cm graded macadam

Scheme3:(Asphalt + Asphalt + HBM)

4cmAC10+7cmAC16+18cmSMA20+30cm limestone soil

And choose scheme2 to check whether it meets requirement.