"This morning, I checked the scene. It turned out that (road subsidence) was due to the mistake of the constructor for building a three-story basement at Siloam Hospital," Chief of the Surabaya City Development Planning Agency Eri Cahyadi stated here on Wednesday.
He believed road subsidence occurred due to the soil retaining wall on the basement of the hospital caving in.
"Judging by the collapse of the soil retaining wall, the phases in the construction (of the basement) did not follow the standing procedure," he stated.
The soil retaining wall was made of soldier piles, or bored concrete piles, placed in parallel to a certain depth, supported by ground anchors and bentonites, he revealed.
"Hence, the soil retaining wall collapsed, as it could not retain the lateral burden from the Gubeng Highway. Consequently, the road subsided," he noted.
He said there was no issue with the construction permit. However, the construction of the project violated the procedure.
Cahyadi noted that his office, along with the contractor of the project, PT. Nusa Kontsruksi Enjiniring, and a team of construction experts from the Surabaya city government will again check the scene to establish the exact cause of the road subsidence.
Reporting by Abdul Hakim, Suharto