Required Excavation

In the case of the underground part of the high-rise buildings open, ie in the pit, separates from the surface of the earth, should take measures to prevent the gap between the end of development excavation and foundation unit high-rise buildings more than two days. 4.13. When working on the installation of foundations in open pits should be taken to preserve the natural structure of the soil base, including, particular: to protect the excavation from entering surface waters (due to a system of drainage from upland watersheds and drainage ditches, sumps, drains, etc.), except that the inflow into the pit through its bottom and sides by the device dewatering system using installations or dewatering wells equipped with submersible pumps, and the devices impervious screens and curtains (FAR), with the exception of dynamic influences at work in the excavation earthmoving machinery and other construction equipment due to the protective layer of soil - shortfall; protection foundation soil from freezing, etc. 4.14. Before the start of works on the foundations should make sure that the actual stratification and soil properties at the base of excavation specified in the project. Soils at the base that do not correspond to the natural occurrence of the required design density and waterproofing shall be using rollers, heavy trambovok and other sealing means. 4.15. During the period of construction of the underground part of the building if necessary, should include event (Expansion joints, etc.), precluding the emergence and development of nonuniform thermal strains in structures in the construction period..