HCM CITY — The HCM City Department of Transport plans to use underground drilling methods on construction works located on 88 main or crowded streets.

The works involve electricity and water supply, installation of telecommunication cables, and flood prevention, Võ Khánh Hưng, deputy director of the department told the Tuổi Trẻ (Youth) newspaper.

Hưng said that past construction work had seriously damaged roads, and, in some cases, had made it more difficult to return the roads to their original condition.

Since the beginning of the year, the inspector of the department has handled 792 violations for not returning the road to its original condition after construction. The total penalty issued was VNĐ4.7 billion (US$203,000).

New underground drilling methods can speed up construction, reduce the area of excavation, cut transportation costs, and prevent traffic congestion and environmental pollution, Hưng added.

In addition, the department has instructed builders to use new technologies instead of old ones.

The three most common underground drilling methods include horizontal directional drilling (HDD), pipe jacking, and tunnel boring machines.

HDD technology is an American method of installing underground pipelines and cables with the fastest construction time, reasonable price, and easily controlled drill bits.

The pipe jacking method, a technique for installing underground pipeline, has a higher price and is suited for environmental projects such as flood prevention work and drainage systems.

The tunnel boring machine is used to excavate tunnels with a circular cross section through layers of soil and rock, suited to the ongoing metro construction.

Võ Kim Cương, former deputy chief architect of the city, said these new methods would help the city reduce costs, improve construction quality and ensure road surface structure and traffic safety.

Most construction woks in the city are using outdated methods which degrade roads, cause pollution and affect people’s lives, Cương adds.

Nguyễn Văn Dung, deputy head of the Urban Transport Management Division No 1, said some construction works had used underground drilling, such as Nhiêu Lộc-Thị Nghè sewer system, and underground cable lines.

However, these methods have not been widely applied, Dũng said.

To ensure traffic safety, the Department of Transport has directed builders to temporarily stop working and quickly return the roads to their original structure for the two-day New Year Holiday (December 31- January 1). — VNS