Homeowners' dreams cave in to subsurface faults

Abu Dhabi: Houses with cracked walls, parking lots with major holes and roads with gaps so deep it's hard to see their depth.

Certain parts of Khalifa City look like an aftermath of a small scale earthquake but in reality it is a project gone wrong.

In response to an e-mail from Gulf News, the municipality admitted the problem in Khalifa City B. It said: "Five houses, which were built in the area before 2002, were damaged because of problems in the subsurface."

The municipality attributed the problems to the cavities and weak layers.

"What caused these cave-ins are actually cavities in the ground," said Nehmi Selbak of Fujian Survey and Geo Research company. "We have done surveying of the area and found ... major cavities in the ground that have caused these cave-ins," Selbak said.

While there are various reasons for gaps in the subsurface level, Selbak said the cavities were created mainly due to last month's five-day rainfall.

"We know that water has the ability to dissolve the salt and other material that is in the ground, thus causing the gaps we call cavities," Selbak said.

Many of these cavities can be discovered through methods like geophysical surveying or digging boreholes. The problem with boreholes is that they only reveal whatever is in the surrounding and nothing beyond.

The municipality has halted further construction on 35 plots and has also decided to compensate some home owners by offering them other plots.

The municipality instructed new homeowners in the area to make six boreholes to test the land. Instead of two, as previously requested, the boreholes are intended to test for cavities in the perimeters of the plot of land.

"We are also instructing contactors to build deep [foundation] for the houses. The municipality is working on a guide book on the technical specifications and a way of surveying land for building in this area," read the statement.

Although the municipality has halted construction on many of the sites, the information on what will be done with these projects has fallen through the cracks.