Estimation of Foundation Base Pressure in Residential Reinforced Concrete Buildings for Use in Geotechnical Design

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ÖZER M., Bektas F.

JOURNAL OF POLYTECHNIC-POLITEKNIK DERGISI, cilt.29, sa.3, 2026 (ESCI)

Özet

In geotechnical foundation design, knowledge of the base pressure transmitted from the foundation of a building to the supporting soil is essential for bearing capacity and settlement analyses. Similarly, in slope stability analyses and the geotechnical design of retaining walls, accurate definition of the foundation base pressure (i.e. surcharge load) transferred to the ground from buildings located at the crest of slopes or retaining walls is of critical importance. In such cases, the most reliable approach is to calculate the foundation base pressure using the loads obtained from the structural analysis reports of the buildings. However, in practice, structural analysis reports may not always be available. Under these circumstances, approximate methods are required to estimate the foundation base pressure. In this study, an approximate estimation of the base pressure transferred from each storey to the foundation in residential reinforced-concrete buildings is proposed for use when structural analysis reports are unavailable. For this purpose, a total of 41 residential reinforced-concrete building projects, designed by different engineering firms after 2018 and intended for construction in various regions of T & uuml;rkiye, were examined. The results indicate that the base pressure transmitted from each storey to the foundation ranges between 11.4 and 21.8 kPa (mean value of 16.2 kPa) for the G+Q load combination, and between 16.4 and 31.3 kPa (mean value of 23.2 kPa) for the 1.4G+1.6Q load combination. Histogram analyses of the obtained data show that the base pressure values are predominantly concentrated in the range of approximately 15-18 kPa for the G+Q load combination and 21-26 kPa for the 1.4G+1.6Q load combination. Consequently, it is concluded that, in geotechnical design calculations where structural analysis reports are not available, the foundation base pressure mayAbe approximately estimated by adopting values in the range of 15-18 kPa per storey for the G+Q load combination and 21-26 kPa per storey for the 1.4G+1.6Q load combination, with the self-weight of the foundation subsequently added to these values.