Construction of prefabricated foundations in complex excavation sites

Abstract

We offer effective technological constructive solutions of preservation of natural characteristics of the soil. According to the research, this can be achieved through organizational and technological solutions. This reduces the volume of earthworks and the cost of backfilling. Such constructive-organizational-technological solutions (COTS) are relevant in the construction of underground parts of kindergartens and educational institutions on shallow foundations.

From experience and research, we know that to introduce natural characteristics of the soil we must use technologies of cumulative construction of earthworks and foundations. It is used for the construction of cast-in-place concrete shallow foundations with different types of manual and mechanized labor. In turn, this technology is not used for mechanized construction of prefabricated strip foundations.

The paper considers the construction of prefabricated strip footings with basement walls from precast concrete blocks. A hypothesis is presented for the technology of combining footing construction with preserving natural characteristics of the soil: to balance construction times using complex mechanized technological processes (CMTP) for two universal machines (UM) on three jobs. UM are: an excavator and a crane. The CMTP are: earthworks and installation of footing slabs and basement wall blocks. The latter is presented in two variants: one or two rows.

This technique was used to give machines full access to the perimeter of excavation site. It proposes the division of the construction into seizures, provides work estimates, identifies the main and secondary jobs for the excavator and crane, and gives formulas for calculating work and time estimates for machines installing basement wall blocks. Given technology is compared with construction from outside of the excavation site, and technical-economic indicators are shown.

We need to research implementation of these techniques for the construction of kindergartens and schools in cramped urban environments.