Comparative calculation of piles taking into account seismic impacts (example in Ho Chi Minh City)

The construction of high-rise building and structures has been widely developed recently in Vietnam. Pile foundations are considered one of the most suitable solutions when choosing the foundations for their construction, especially in difficult geological conditions, including seismic areas. According to many researches, geological conditions of Ho Chi Minh City are generally difficult. The occurrence of earthquakes there influences the conditions for the construction. Besides, many historical cases have shown that soil liquefaction is often manifested, negatively affecting the underground structures and foundation working. With an increase in investments of international construction companies and organizations in Vietnam, pile foundations can be designed according to domestic or foreign normative documents. Therefore, at present, a better understanding and detailed analysis of various existing normative documents and methods for designing pile foundations are required, especially when the influence of soil liquefaction is taken into account. This paper presents a review of various normative documents, including Russian, Vietnamese, American and Eurocode. The different methods in these normative documents for calculating the piles' bearing capacity are considered in 2 cases: with and without taking into account the soil liquefaction based on the hypothesis that the additional downward loads due to self-compaction of liquefiable soils affect piles. Finally, a comparison of the calculation results is presented. The comparison shows how these considering methods in these normative documents differ from each other and how much the pile's bearing capacity can be reduced when considering the soil liquefaction in calculations.