City told to survey soil characteristics

Indah Setiawati ,  THE JAKARTA POST ,  JAKARTA   |  Fri, 06/26/2009 1:13 PM  |  City

Experts reminded governor Fauzi Bowo to pay attention to the geological aspects of land and buildings ahead next year's construction of the Mass Rapid Transportation (MRT) subway system.

"We have to take into account that the land characteristics in North Jakarta and South Jakarta are different so the buildings can survive damages," Danaryanto, head of the Geology environment division at the Energy and Mineral Resources Ministry, said Thursday. He said the middle areas that divided the southern and northern parts were Rawa Buaya in West Jakarta, Monas and Cempaka Putih in Central Jakarta.

The southern part, he said, was more solid because it was made of hard volcanic alluvium, while the Northern part was softer because it consisted of beach alluvium.

Danaryanto said the establishment of the MRT in the northern parts would require high technology in underground construction.

"I think the engineers understand the solution better than us."

He said Fauzi told him according to the plan, some of the MRT tracks would appear above the ground in some parts of the soft land area.

Dodi Mudohardono, another geology expert, said the administration had made a good decision to plan the first construction of MRT stations along the Lebak Bulus - Dukuh Atas route, located on the southern part of the middle areas.

He said areas along Dukuh Atas and the National Monument featured hard and soft soil layers altogether. Dodi said the MRT lanes would be constructed down some 40 meters, reaching the groundwater reserve.

"The construction of the MRT lanes should take into account water reserves as well as the flow of groundwater. Otherwise, the lanes could affect the reserve and the underground flow of water."

He added groundwater flowed from the southern part of the city to the north and that intensive research was needed if the administration wanted to build a route against the flow like a west to east one.

The first MRT construction will see 12 stations along the Lebak Bulus-Dukuh Atas route, comprising eight elevated stations on a 10.5-kilometer stretch of track above ground, and four stations on a 4-kilometer stretch underground.

The track will run from Lebak Bulus and pass through Jl. Fatmawati, Jl. Cipete Raya, Jl. Haji Nawi, Blok A, Blok M, Jl. Sisingamangaraja and Senayan. It will continue through underground stations in Istora, Bendungan Hilir, Setiabudi, and Dukuh Atas.

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