Determination of characteristic values of soil parameters in foundation design standards in Vietnam

Abstract

Vietnam is currently in the process of developing and improving its national standards (TCVN) for the construction industry, many of which are adapted or referenced from international standards. However, significant inconsistencies remain among existing standards, particularly in the calculation methods for determining and applying the characteristic values of soil parameters in foundation design. This study reviews and compares the relevant provisions of current Vietnamese standards (TCVN) with those of international standards. The results indicate that the TCVN standards are not yet consistent in defining and applying characteristic values and reliability factors in geotechnical calculations. Although both TCVN 9362-2012 and TCVN 10304-2025 specify characteristic values, their differing approaches lead to variations in calculated results, affecting the reliability and uniformity of design outcomes. The findings clarify the fundamental principles behind the calculation methods used in these standards and emphasize the urgent need to systematize and harmonize TCVN geotechnical standards. Developing clear, user-friendly, and harmonized standards will enhance the effectiveness of design, management, and implementation in construction practice in Vietnam.