Week 1 Challenge

Q1. DESIGN SUMMARY REPORT (DSR)

INTRODUCTION

The Design Summary Report consists of necessary data and justifications for introducing the new road project. It also narrates the systematic approach of designing a project from the concept stage to the Final Design.

ROADWAY DETAILS

Name of the Roadway: Muscat Expressway

Location: Muscat Governorate, Sultanate of Oman

Length: 54kms

Limits: Al Qurum signalized junction to Al Rumais Interchange, Al Barka

TYPE OF WORK

The proposed project is a new construction and the prosed alignments will run parallel to existing Sultan Qaboos 4 lane highway from Al Qurum to Al Barka.

CLASS OF ROAD

The proposed Roadway is an Expressway consists of 3 lanes on each direction with minimum lane width of 3.75m, 2m paved shoulder towards centreline and 3m paved shoulder towards the outer edge. The proposed minimum median width is 6m and varies up to 12m at various locations.

DRAINAGE AND STRUCTURAL DETAILS

Open drains are proposed on the outer edges and in the medians with 10:1 slope and median drains will be connected with cross drains at 100m intervals. The proposed road will have 13 major interchanges, 1 major bridge, 32 MSE walls, 300 multiple cell box culverts and 720 pipe culverts.

RIGHT OF WAY

Right of way of the road typically varies from 80m to 125m.

UTILITIES

The initial 8km section is passing through populated areas and the right of way consists of major Crude Oil pipelines, LNG pipelines, Sewage lines, Major water distribution networks, High Voltage Electricity Pylons & Major underground electricity distribution cabling network and major fiber optic telecommunication networks.

TYPE OF TERRAIN

Almost 80% of the proposed alignment is passing through hilly terrains and the remaining part is consists of plain terrains.

GEOMETRIC DESIGN

The new roadway alignment has been proposed in order to reduce the traffic congestion in Sultan Qaboos Highway and the proposed alignment will be having a max speed limit of 120km/hr and minimum speed limit of 80km/hr. The minimum radius of horizontal curve has been fixed as 600m and the maximum superelevation has been fixed as 7 percent. All the geometric design elements have been fixed in line with the latest recommendations from Oman Highway Design Manual (HDM).

TYPICAL CROSS SLOPE, DITCH & SIDE WALKS.

Typical cross slope for the proposed alignment has been fixed as 2 percentage and slope for the diches has been fixed as 10:1. The provision of sidewalks has not been provided for the proposed roadway except the pedestrian crossing underpasses at selected locations which has access to the nearby distribution roads.

VERTICAL CLEARNCES AND MAXIMUM FILL HEIGHTS

The vertical clearance for all structures has been fixed as minimum of 5.5m as per the Oman Highway Design Manual (HDM) and maximum fill height of the embankment without a retaining wall has been restricted to 6.0m as per the HDM standards.

Q2 (PART 1)-TYPICAL ROADWAY PROJECT LIFECYCLE WORKFLOW

A typical roadway project lifecycle workflow contains multiple stages of Data collection, Engineering & decision-making process and these various stages are listed below.

• Design Summary Report
• Topographical Survey
• Development of typical Sections
• Geometric Design (Design of Horizontal Curves and Vertical Curves).
• Superelevation Design
• Production of final drawings (Plan set and Detailed Design).

Q2 (PART-2)

Multiple Agencies involved in a Roadway Project Workflow is listed below,

• Survey agencies ( For the existing data collection from the concept stage till the completion of project).
• Roadway Design Consultancy
• Drainage Design Consultancy
• Bridge/Structural design consultancy
• Utility Designers.
• Traffic Designers
• Geotechnical consultancy.

Q3.PART-1

The important points to be noted while fixing the alignment are

1. Alignment should be consistent
2. Alignment should be safe
3. Alignment should consider the environmental impact
4. Should properly study the effects on fabric of community
5. Alignment should be useful to the Highway user.

The Basic elements of a Horizontal Curve are

• Curve Radius
• Superelevation Rate

This means the curve should be smooth, safe and aesthetically pleasing. Also caution should be taken while providing compound curves in front of simple flat curves.

Vertical curves provide gradual changes between tangents of different grades and the basic elements of vertical alignment are listed below.

• Grades
• Vertical curves

Q3.PART 2

Vertical curves are required to gradually connect (or to provide smooth transition) between tangents of different grades.

Q3. PART 3

Attachment

Q4.PART-1.

Superelevation is provided in order to counterbalance centrifugal force acting on a vehicle traversing in horizontal curve.

Q4.PART-2

Attachment

Q5. Typical Road Project set of submission consists of

• Cover sheet
• Index page
• Project Layout
• Typical sections
• Plan & Profiles
• Detailed design cross sections
• Traffic drawings
• Drainage drawings
• Utility drawings
• Structural drawings
• Road signage drawings

Q6.

Attachment