Прогноз дополнительных деформаций зданий и сооружений в процессе высокочастотного вибрирования шпунтовых свай

Abstract

The main criterion of safe construction for the underground space development in conditions of dense urban environment is the right selection of enclosing structure of the excavation pit. One of the most common types of the pit enclosing designs is a construction of metal sheet piles driven by high-frequency vibratory loading. It is generally believed that the technology of high-frequency vibratory loading and extraction of piles has no significant impact on the surrounding soil mass and structures of buildings and facilities located in the active dynamic zone. However, numerous examples of additional deformations of buildings emerging even before the stage of the pit excavation starts, witness, that the technological settlement can be as significant as 3-5 cm. The author presents some methods of analytical and numerical forecasting of additional deformations of buildings located in the zone of influence in the process of vibratory driving or extraction of piles based on the hypothesis of vibration-caused creep of dispersed soils. A large amount of deformation is due to the complicated engineering and geological conditions of St. Petersburg. It is in the thickness of weak water-saturated clay soils of soft-plastic, flowable-plastic and flowable consistency that the greatest values of additional deformation can develop. Verification of the developed methods is confirmed by comparing the calculation data with the results of monitoring the values of additional deformations.