SEASONAL SOIL FREEZING IMPACT ON FOUNDATIONS OF BUILDINGS (LIQUEFIED HYDROCARBON DEPOT TERMINAL)

Abstract

The paper presents the analysis of the influence of seasonal freezing and thawing of clay soils on structural deformation. Studies are performed at the construction site of liquefied hy-drocarbon depot terminal. Additional surveys are carried out after the winter construction peri-od. In autumn and winter, loam was frozen at the base of the foundations. In spring and sum-mer, pit soils were soaked with meltand storm-water. On the pit walls erosion developed tie-in flows of meltwater at the bottom of the pit, which led to significant deviations from the de-sign position of the erected depot foundations, which were dismantled, and the concrete prepa-ration for retaining walls was destroyed almost everywhere. The study shows that the subsidence properties of loams degrade after soaking. It is there-fore unnecessary to reduce drawdown of designed and partially executed expensive measures. Initially, under the ground horizontal depots and retaining walls pile foundations are con-structed. Finally, foundations are erected in open pits with a depth of 4.0–5.8 m of monolithic reinforced concrete on a natural base. For the latter option, the project requires a large amount of excavation works at the open pit with a volume of about 10 thousand cubic meters and re-placing them by the same volume of compacted coarse-grained marble sand and gravel. It is shown that the most efficient and reliable option are pile foundations with a high grillage and also effective anti-rubble measures developed in TSUAB. In the pile variant, it is proposed to use piles 8 and 9 m long with a permissible load of 250 kN and 260 kN, respectively. The de-veloped proposals can be applied in the construction of the 2nd stage of the depot terminal.