Karaganda apartment building collapsed because of uneven settlement of foundation

Results of investigation of reasons that caused the 5-storey building to collapse in Bessoba residential complex of Karaganda were unveiled today, May 15. “Development of unacceptable foundation settlement caused by soil swelling” was tagged the main reason behind the collapse, Tengrinews.kz reports. “According to the statements of the expert organizations, the main reasons of the building's collapse were: 1. Lack of measures to prevent swelling of soils from affecting the building’s steadiness, 2. Development of unacceptable uneven settlements of the foundation because of the soil swelling caused by lack of water retaining activities. 3. Insufficient hardness and load bearing capacity of the en bloc reinforced concrete framework of the building in the actual engineering-geological conditions,” the act states. The experts also tagged several additional reasons that accelerated the collapse of the building in Bessoba complex: - First of all, this is low concrete strength in 74 columns and 59 beams at the basement, 14 columns and 12 beams of upper floors. - The second reason is lack of due transversely stiffness of the building, because the actual construction solution of the second block of building No.7 does not fully comply with the design. - The third reason is in low-quality joints of the bearing structures of the basement: most of them were made in violation of the technological rules of concrete casting. In particular, longitudinal reinforcement joints have not been coated with concrete and the concrete mass contains different foreign agents like expanded foam, pieces of timber and rocks. - The forth reason lays in the outside drainage pit along the G axis on the outside of the second block of building No.7. This pit facilitated the seasonal frosts in penetration of the soil and boosted the impact of flood and technogenic waters on the foundation’s bottom. Earlier Tengrinews.kz English reported that 5-story residential building No.7 of Bessoba residential complex, constructed 3 years ago as an equity construction project, collapsed in the morning of April 6.