Abstract: Most silo foundation failures occur when it is loaded for the first time. Pressures rise in the pore water which reduces the frictional component between the particles and hence cause a reduction in the shear strength of the soil. If, at maximum load, the applied stresses are greater than the shear strength of the soil, the soil fails. It is normal for the tower to overturn with failure taking place along a circular arc. If the foundation does not fail during the first loading the structure will be stable for subsequent loadings. To determine bearing capacity of a soil shear strength, measurements are required to a depth below the footings equal to 2/3 the diameter of the foundation. Shear strength may be measured in the field by means of a field vane or cone, or in the laboratory by unconfined compression or triaxial strength tests on undisturbed samples of the soil. Adequate attention should be given to the reinforcement of the ring foundation, the quality of concrete, the centering of the silo on the footing and the interaction of silo groups which should not be closer than the diameter of the silo.
Canadian Building Digest; no. CBD-177, ISSN:
0008-3097, Publication date:
1976-05
