Preserving environment: CDA alters design of I-8 interchange

Replaces idea of mechanically stabilised earth walls with traditional method.

ISLAMABAD:

The Capital Development Authority (CDA) has introduced changes in design of the under-construction interchange at Sector I-8 on the Islamabad Expressway in a bid to preserve the environment and reduce cost.

The authority had come under criticism for launching the expressway expansion project without carrying out an environmental impact assessment and obtaining approval of the Pakistan Environmental Protection Agency (Pak-EPA).

Currently, the work is under way on phase-I of the project, which includes rehabilitation and expansion of the existing roadway from Zero Point to Faizabad, along with the construction of an interchange at the Sector I-8 intersection. Cost of the first phase of the project is Rs 1.6 billion.

The project, estimated to cost Rs21.8 billion and to be completed in three phases, was inaugurated by Prime Minister Nawaz Sharif on June 30, 2015.

The Capital Development Authority (CDA) Member Engineering Shahid Sohail said the changes are aimed at reducing the cost and to preserve greenery as directed by the prime minister.

Construction of mechanically stabilised earth (MSE) walls around loops of the proposed I-8 intersection, a major component of the proposed interchange, has been slashed.

MSE walls stabilise unstable slopes and retain the soil on steep slopes and under-crest loads.

“It will help reduce the first-phase cost by Rs400 to Rs450 million,” Sohail said, adding that MSE walls usually consume large chunk of land which could have affected the area’s greenery.

He said CDA has now opted for traditional soil enforcement method used at Zero Point and Faizabad interchanges.

However, a senior engineering wing official said introduction of changes after tendering process was a violation of the contract. He said by removing MSE walls, the interchange will be vulnerable and less resistant. He gave the example of Zero Point interchange where road structure faced settlement and depressions have appeared.

However, Sohail said the consultant had suggested both options in the original design.

The civic agency is expecting to complete first phase of the project by December this year. CDA has allocated Rs5 billion for the project in its 2015-16 budget.

Phase-II

Meanwhile, three construction firms on Tuesday presented technical bids to CDA for the Rs6.6 billion phase-II of the project.

This includes up-gradation of the highway between Faizabad and Airport Chowk. Two new interchanges — one each at Swan Chowk and Airport Chowk — along with dualisation of service roads, and an underpass at Kuri are also part of the phase-II.

The three firms are that presented bids are the National Logistics Cell, ZKB, and the Frontier Works Organisation.

Unlike phase-I, the second phase will be constructed on a design and build basis. In this model, the construction firm not only prepares the project design but also executes the project.

“Firms qualifying on technical grounds will be asked to submit their financial bids for the project, and the firm filing the lowest bid will be awarded the project,” the official said. This process can take two months.

Under the project, public transport plying on the expressway will be shifted to service roads the and main road would be available for private vehicles only.

An official who attended the presentations said all three firms along with their design consultants briefed CDA about their technical bids.

The phase-III of the project which is estimated to cost Rs13.167 billion will include construction of additional lanes and complete highway rehabilitation between Airport Chowk and Rawat. Tendering process for this phase is yet to be undertaken.

Published in The Express Tribune, August 19^th, 2015.