Work to fix subsidence problems at Shanghai International Circuit will be completed by the weekend - well ahead of next month's Formula One China Grand Prix.

Renovation work, including laying asphalt, will take several more days, said officials with project operator Shanghai No.1 Engineering Co Ltd. Once complete, this will ensure good track conditions for the next seven years, they said.

Subsidence was found to be especially serious at bends No. 1, 8 and 14 and was blamed for causing vehicles to jolt as they took these corners. Current work will ensure the circuit will no longer be bumpy and the subsidence problem will be solved, engineers said.

Repairs will cover 6,100 square meters of the circuit, including four turns and a 800-square meter speed-buffering zone.

The China Grand Prix will be staged from April 15 and 17. But the circuit must pass an inspection by officials of FIA, Formula One's governing body, before it can go ahead. Organizers Juss Event was confident that "there should be no problem" passing the FIA exam and that the grand prix will go ahead as scheduled.

Juss Event manager Yang Yibin said subsidence is to be expected because the circuit is built on soft ground - a geological feature of Shanghai - and also a result of hosting seven Formula One grands prix and other high-intensity racing events over the years.

The site's engineering manager said the Shanghai circuit was designed with sharp height differences to add to driving challenges and make races more exciting.

The designs adopted to facilitate the height differences cause subsidence to take place naturally as time goes by, said the manager. By relaying asphalt, it is relatively easy to solve this, he added.

The Shanghai circuit was designed by Hermann Tilke. A single lap is 5.5 kilometers, while the stadium can seat 200,000 spectators.