Vertically loaded foundations in tamped trenches and calculation of their bearing capacity

The interaction between foundations in tamped trenches (FTT) and the soil bed are investigated experimentally and theoretically. The relationship between the resistance of the FTT and volume of tamped-in crushed stone, the strength of the soil bed, and the dimensions of the tamper is established. Principles for assignment of the limiting settlement for which the limiting resistance of the foundation is determined from the results of static tests are indicated. A procedure is proposed for determination of the bearing capacity of FTT from static-penetration data. Translated from Osnovaniya Fundamenty i Mekhanika Gruntov, No. 5, pp. 19–23, September–October, 1996.     

Interaction between shallow foundations in tamped (punched) trenches and heaving soil

Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 4, pp. 14–16, July–August, 1989.     

Foundations with micropiles in tamped trenches on construction projects in belarus

A procedure is presented for the installation of foundations with micropiles a distinguishing characteristic feature of which is the tamping of a trench and its concreting with a group of micropiles under an embedded grillage. A set of field investigations under different soil conditions, which has indicated the reliability of these foundations and their effectiveness for the construction of any buildings and structures, is described. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 5, pp. 7–10, September–October, 1995.     

Approximate modal analysis of multistory symmetrical buildings with restricted inelasticity

Simplified capacity curves are presented for modal decomposition of multistory inelastic cantilever bents. These structural systems are uniform over the height and plasticity is assumed to be restricted into the beams, since significant rotation ductility factors may be attained in these members without loss of strength. The approximate method of modal decomposition of multistory inelastic bents is based on the concept that the total response may be obtained from the contributions of equivalent nonlinear single‐degree‐of‐freedom (SDOF) modal systems, in combination with the technique of modal superposition. In particular, the contribution of the first mode equivalent inelastic SDOF system is examined, since its modal contribution is of higher importance. The response of such SDOF systems basically depends on their capacity curve, which may be formulated by using the dynamic properties (frequency, effective modal mass and mode shape) of the initially elastic bent, as well as the corresponding properties of the bent when the entire set of coupling beams is assumed to be yielded. The procedure is presented for plane cantilever bents, but it can be easily extended to symmetrical structural systems composed of different types of inelastic bents. Its application is illustrated by means of a 10‐story inelastic coupled‐wall bent subject to a strong earthquake motion, equal to 1·5× El Centro N–S ground excitation, and the results compare well with those obtained from a step‐by‐step nonlinear time history analysis of the discrete member model. Copyright © 2007 John Wiley & Sons, Ltd.     

Estimation of bearing capacity and settlement of shell foundations on tamped beds

A dynamic method of evaluating the bearing capacity of shell foundations on a tamped soil bed is examined. Results are presented for full-scale tests under field conditions. A computational formula is proposed for determination of the bearing capacity of a shell foundation based on residual and elastic refusal during tamping. A method is proposed for approximate estimation of expected settlement based on on-site cone penetration of the soil under in-situ conditions.