Analysis of modern research of shell foundations on a round plan
Abstract
The use of shells as foundations has attracted significant scientific and practical interest around the world. Previous studies have proven their higher bearing capacity and lower draft compared to solid slab foundations. Shell foundations are also more effective in situations involving the transfer of significant loads to weak foundation soils, as well as for structures that accept large wind and seismic loads, such as telecommunication and silos, chimneys, and others.
The need to know modern constructive solutions for foundations-shells, their behavior under the influence of an increasing load in a complex stress-strain state on various foundations, makes the task of studying, systematizing and developing their effective practical application urgent.
The article explores the experimental and theoretical studies of foundations-shells round in terms of various structural schemes on various soil foundations. Experimental models are considered that were loaded with a concentrated force at the center of the conical shell, as well as along the support ring of the spherical shell. For a spherical foundation-shell, the effect of edge restraint on the stress-strain state has been studied.
The results of tests on wire-reinforced KF-O models under the action of a concentrated force showed rather high values of the ultimate load. An increased height-to-radius ratio (f / r2) for the foundation body from 0.25 to 0.75 increases the final load of the foundation by about 15%. The tapered shell can perfectly withstand the smaller random load eccentricities (through unpredictable torque) that can occur in practice.
On EM №1 it was found that more than 75% of the total subsidence of a round slab is localized in the surface layer 0.6 meters deep (0.5D). The boundary of the deformation zone slightly exceeds 2D. For F-O, more than 60% of the total subsidence is localized in the surface layer with a depth of 0.4 meters (0.3D), and at a depth equal to D, up to 75% of the total subsidence is localized. The boundary of the deformation zone is 1.4D.
The analysis of the results of experimental studies to determine the ultimate loads on models of reinforced concrete round foundations-shells on different soil foundations for various structural schemes is carried out. Experimental models modeling the foundations-shells on which the columns of buildings and structures rest, as well as models of tower structures, where the load is applied to the outer ring support, are considered. In each case, a comparison is made with round slabs and shows the advantage of shell foundations.
