代写CEGE0030 – ROADS AND UNDERGROUND INFRASTRUCTURES 2024-25代写C/C++编程

日期：2025-02-05 05:22

CEGE0030 - ROADS AND UNDERGROUND INFRASTRUCTURES

Academic year: 2024-25 Assignment: Coursework on Roads Weight: 20%

Deadline: 7th  of February 2025, 2:00 pm

Type of submission: Electronic copy (in Turnitin, Moodle). Only one student per group submits.

Type of assignment: groups of 3 students

Word count limit: 2,500 words excluding reference list, tables, graphs and figures, and appendices

Brief:

The  objective  of this  project  is  to  design  a  new  road  in  the  area  of  Sheffield,  alignmening  with infrastructure development priorities in the Midlands and Northern England. The road connects two villages and comprises two lanes (one per direction), with a total daily average traffic flow of 9,500 vehicles (70/30% split). The traffic study indicates that 35% of vehicles are heavy, with each tupically having three axles. The road’s design life is set at 40 years.

The chosen cross-section is on a straight reach of the road (no curvature in the plan view), and the alignment raises the road elevation by 1.2 m above the natural ground level.

Materials and Geotechnical Conditions

•    Natural Ground: Moderate plastic clay (CH), with:

o California Bearing Ratio (CBR): 5%

o Maximum Dry Density (Proctor Test): 1620 kg/m³ (15% water content)

o Bulk Gravity: 2670 kg/m³

o Natural Water Content: 25%

•    Local Material Availability:

1.    Poorly Graded Sand (SP) (3 km away):

o CBR: 27%

o Optimum Dry Density: 1950 kg/m³ (10% water content)

o Bulk Gravity: 2650 kg/m³

o Natural Water Content: 8%

o Suitable for subgrade but not as base or subbase.

2.    Well-Graded Gravel with some fines (GW) (15 km away):

o CBR: 85%

o Optimum Dry Density: 2100 kg/m³ (7.5% water content)

o Bulk Gravity: 2650 kg/m³

o Natural Water Content: 6%

o Suitable for subbase but not as a base layer.

•    Cross-Section Details

o Lane Width: 3.8 m per lane.

o Shoulder Width: 1.5 m each side.

o Pavement Lateral slope: 1:1.2.

o Embankment Laterail Slope: 1:1.5 (V:H).

o The  pavement  layers  are   homogeneous  across  the  full  cross-section,   including  the shoulders.

Required Tasks

1. Pavement Design

Use the  classical  CBR  methodology to  design  a  flexible  pavement  solution.  Specify  the  materials selected for:

•     Subgrade

•     Subbase (if needed)

•     Base

•     Surface layers

Include across-sectional engineering plot with descriptions of materials, sizes, and units. Justify your solution and why this better than other options, based on cost effectiveness, construction procedures, environmental aspects, etc.

2. Embankment Analysis

Assume:

•     All layers are compacted to 95% of their optimum dry density.

•     The phreatic level aligns with the current natural soil level.

•     Embankment water content is initially at its natural level. Determine:

•     Final void ratio, dry density, and density with moisture for the embankment material.

•     Effective vertical normal stress at the subgrade level.

•     Elastic settlement of the natural soil due to embankment and pavement weight.

3. Rainfall Impact Analysis

Assume:

•     Lateral drainage is blocked.

•     Longitudinal road slope is null.

•     Rainfall  intensity  equals  the  average  daily  rate  for  Sheffield  over  three  consecutive  days (source:Met Office).

Evaluate: whether the water level will reach the subgrade and recalculate effective normal stresses after the rainfall.

Updated Costs of the materials

The following costs reflect current UK market rates (as of January 2025):

1. Transport of Embankment Material: £2.0/m³ per km.

2. Compaction (to 95% Modified Proctor): £65/m³ .

3. Hydraulically Bound Layers: £90/m³ (final density: 2400 kg/m³).

4. Granular Material for Base: £60/m³ (final density: 1950 kg/m³; CBR: 90%).

5. Granular Material for Subbase: £40/m³ (final density: 1750 kg/m³; CBR: 55%).

6. Asphalt Concrete: £135/m³ (final density: 2500 kg/m³).

For additional costs are needed, include sources and justification.

References

Provide all sources used for calculations, material costs, and rainfall data in your report.

Note: Ensure all assumptions are justified, and calculations are clearly presented for full transparency and credit allocation.

Use of Generative AI:

The use of Generative AI (GenAI) is permitted for the review and improvement of the style of your report. However, it should not be used for performing calculations or generating results. Ensure that all calculations and results are your own work.

Figure 1. Compaction curves (PM) for the three possible subgrades