Experience in the construction of a basement sump
A test building is located at the bank of Wenyu River, Tongzhou District, Beijing. It is a frame shear wall structure with three floors above the ground and one floor underground. It is mainly used for the energy conservation, weather resistance, aerodynamic performance evaluation and other tests of building doors, windows and curtain walls. According to the technical requirements of green and energy saving, the whole building is designed to use solar energy, geothermal air conditioning and other energy-saving technologies and equipment, and the design and construction requirements are extremely high. After the completion of the main structure of the building, according to the design change, the circulating water tank, fire water tank, heat storage tank, equipment room, air conditioning system, etc. originally located in the external foundation pit of the building will be moved to the first floor underground, so the original basement must be comprehensively waterproof. The waterproofing of the original basement floor and side wall mainly relies on 4+3mm two layers of SBS modified asphalt coiled material and 500mm thick S12 impermeable reinforced concrete. The interior of the basement is not subject to waterproofing treatment. The concrete construction quality of the original building is good, and there is no leakage before the waterproof reconstruction. After we undertook the task of waterproof reconstruction, we first carried out waterproof treatment on the parts liable to leakage such as steel bar truncation and pipe root on the surface of the basement, and combined with the actual situation of the project with many water pools in the basement, we applied permeable crystalline waterproof coating, JS waterproof coating and polymer cement waterproof mortar to protect the bottom plate, top plate and side wall in turn. In the project, the biggest technical difficulty lies in the construction of three sump pits in the basement. Some experiences and lessons from the construction are summarized and shared with peers, and criticism and correction are welcome. The three sumps are located in the basement fire water pump room, fire pool and solar energy heat storage pool respectively, and their dimensions are roughly L ´ W ´ H = 1m ´ 1.5m ´ 1m. It is required that the new sumps be integrated with the original floor without leakage, and the construction period is initially set as 45 days.