KINGDOM OF SAUDI ARABIAArriyadh Development AuthorityRIYAD

السعودية العربية المملكةالعلي ـئـــيـاله ا ــة

الري رـلتطوي اضـمدينة

ASSOCIATED CONSULTING ENGINEERS

Project Description

The Upgrade of King Abdullah Road Project will provide a continuous 5.3 km Urban Freeway in Riyadh from Prince Turkey Road to King Abdulaziz Road.

The 5.3 km segment will complete one of the remaining gaps of grade separated intersections in one of the most congested corridors in the Kingdom’s capital. Existing traffic in the project area is mostly stop and go throughout the day.

Project Purpose and Need

The primary purpose of the proposed project is to:

Reduce existing and forecast traffic congestion on king Abdullah Road between Prince Turkey Road and King Abdulaziz Road. The project is expected to enhance traffic operations by adding freeway level capacity in an area that currently experiences heavy congestion, and is expected to see increased congestion in the future.

Improve both existing and future mobility and enhance safety throughout the corridor, while minimizing environmental and economic impacts. The project will:

ease congestion, improve mobility by moving almost twice as many cars, decrease commute times for all drivers, enhance traffic safety, and reduce air pollution.

Prince Turkey Underpas s

Takhas s us s i Underpas s

King Fahd Tunnel Olaya Tunnel

Prince Ahmad Inters ection

King Abdul Aziz Underpas s

Project Phases

Detour of Classical Construction

Top-Down Construction Methodology

The “Top-Down” construction approach was primarily devised for existing structures short of space (parking, offices, utilities etc..) such as the existing building may remain in place and its activities uninterrupted while the additional construction works and expansion is happening beneath it. Later it was adopted to other construction industries such as highways, bridges, and even new buildings where significant benefits may be achieved by adding the ability to proceed with construction in both directions at the same time, starting at the ground surface.

In existing buildings or structures, where appreciable loads are present on the existing foundations, micropiles will be required to retain the sides of the excavation and to transfer the vertical loads onto a new bearing stratum taking into consideration differential settlement and its effects on the structure. Normally such works are very sensitive and require high technicity and expertise.

Design principle

Step One:

Drill the 60 cm piles, 150 cm on centers, install the piles reinforcement cage, and cast concrete up to the bottom level of the (60x146) pile cap.

Step Two:

Install the reinforcement cage of the (60x146) pile cap.

Design principle

Step Three:

Cast 20 cm of the 146 cm depth of the pile cap to provide seating for the pre-cast pre-stressed beams.

Design principle

Step Four:

Place the (60x100) pre-cast pre-stressed beams, seated 3 cm on the 20 cm cast portion of the pile cap. One beam is placed every 150 cm, i.e. one per pile.

Design principle

Step Five:

Lay the 6 cm pré-dalle seated 3 cm on the top of the pre-cast pre-stressed beams.

Design principle

Step Six:

Place the reinforcement of the 20 cm topping slab, anchored in the pile cap reinforcement cage.

Design principle

Step Seven:

Cast the topping slab along with the pile cap.

Design principle

Top-Down Construction Stages

A view of thearea just underneath the building showing the light on theother side

Top-Down Construction Applied to Existing Buildings

Top-Down Construction Applied to Existing Buildings

View of thebuilding’sfaçade

Utility Detour

Proposed Detours

Duration: 18 days (100 piles and 2 drilling machines)

Lanes lost: 1 lane of the service road for each direction

Proposed Detours

Duration: 18 days (100 piles and 2 drilling machines)

Lanes lost: 1 lane of the service road for each direction

Proposed Detours

Duration: 18 days (100 piles and 2 drilling machines)

Lanes lost: Zero (Compensated by the median between service road & freeway)

Proposed Detours

Duration: 18 days (100 piles and 2 drilling machines)

Lanes lost: Zero (Compensated by the median between service road & freeway)

Proposed Detours

Duration: 15 days drilling (80 piles) & 20 days slab works

Lanes lost: zero

PILES DRILLING STAGE 5

SLAB WORKS STAGE 1

Proposed Detours

Duration: 20 days excavation

Lanes lost: Zero

SLAB WORKS STAGE 2

Proposed Detours

STAGE 3

FREEWAAY WORKS AFTER INTERSECTION IS REINSTATED

Proposed Typical Sections

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TYPICAL SECTION

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TYPICAL SECTION

AT AMIR TORKEY TUNNEL

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R.O

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Typical section

At underpass

Proposed Typical Sections

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Proposed Typical Sections

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TYPICAL SECTION BEFORE KING FAHED AND AFTER OLAYA INTERSECTIONS

WHERE CLEARANCE BELOW 5.6m

Proposed Typical Sections

Typical Sections

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TYPICAL SECTION BEFORE KING FAHED AND AFTER OLAYA INTERSECTIONS

WHERE CLEARANCE EXCEEDS OR EQUALS 5.6m

Proposed Typical Sections

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R.O

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R.O

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Typical section

At tunnel

Proposed Typical Sections

Analytical Preparation Works

Topographic survey for existing roads and buildings- Geometric- Levels

Underground utilities survey Verification of Dornier's design Research and proposing of an alternative construction system Introducing two support system instead of one system to provide future construction flexibility

- LRT stations- fly Overs

Testing traffic model Coordination with relevant authorities

Design Criteria

Design Criteria

Design Criteria

Design Criteria

Design Criteria

Raising LRT at Prince Ahmad Intersection Finalizing the LRT access opening size and location Providing LRT rails and stations loading on King Fahd/Olaya Tunnel

OUTSTANDING ISSUES

Methodology for Traffic Assessment

In the macro-simulation- Check the traffic volumes - Determine the impact of detours (speeds and capacities)- Identify the diversion points and routes (by pass)

Tests of the options of detours in a micro-modeling tool - Determine the Level Of Service (LOS)- The design of the new intersections- Traffic optimization- Reduce as possible the impact of the works

Detailed detour plans and the required signage

Sample Run

As per Highway Capacity Manual (HCM), the adopted Level of Service (LOS) are:

- A speed >=41 kph - B speed >=32 & speed <41 kph

- C speed >=23 & speed <32 kph

- D speed >=18 & speed <23 kph

- E speed >=14 & speed <18 kph- F speed <14 kph

Microscopic Simulation

Microscopic Simulation

Microscopic Simulation

Microscopic Simulation

Microscopic Simulation

Microscopic Simulation

PM: 1 LaneMicroscopic Simulation