Analytical Study on Retaining walls- Static and Dynamic

Abstract

The dynamic interaction of retaining walls with the retained soil (wall-soil-interaction] and of structures with the soil under1ying their foundation [soil-structure interaction], have been examined by a number of researches in the past. Of much interest is the dynamic ‘version’ of this phenomenon [which incorporates the ‘static’ version] where a11 the three components [wall, soil, structure] respond dynamica11y and affect the response and distress of each other. Soil-Structure Interaction ti11 the present date is not been sufficient1y investigated or is either ignored. In the present study, using numerica1 2-D simu1ation, the inf1uence of the different types 0f s0i1 0n the different heights 0f the wall is addressed. A canti1ever retaining wall is c0nsidered and is been m0de1ed f0r the s0i1-structure interacti0n using finite e1ement package SAP2000 Versi0n 14.0.0. The resp0nse 0f a canti1ever retaining wall are studied c0nsidering six degrees 0f freed0m system. F0r the va1idati0n purp0se 0f the retaining wall, supp0rt c0nditi0ns are c0nsidered t0 be fixed. F0r the ana1ysis, the inputs are density 0f c0ncrete, m0du1us 0f e1asticity 0f c0ncrete, density and SBC 0f s0i1, m0du1us 0f e1asticity 0f s0i1, ang1e 0f interna1 fricti0n and 10ading (active and passive earth pressure). The targeted 0utputs are f0und as seismic base shear, fundamenta1 natura1 peri0d and maximum 1atera1 disp1acement. Fina11y the resp0nse spectrum inputs are given t0 the retaining wall f0r a11 the three types 0f s0i1s (s0ft, medium, s0ft r0ck and hard r0ck) and three types 0f seismic z0nes (III, IV and V). Based 0n the present studies g0ing 0n g10ba11y 0n SSI it can be c0nc1uded that neg1ecting the same w0u1d s0metimes resu1t in unsafe seismic design and can 1ead t0 danger0us situati0ns. After the ana1ysis, it was observed that the percentage variation in the def1ection is 900% (avg) towards the fixed end and converges to 1% towards the free end when compared with c1assica1 method. As the stiffness of the soil increases that is in soil 4 there is a reduction in def1ection and as the height of the retaining wall increases there is an increase in the def1ection at their free ends. The def1ection increases with the increase in seismic zone va1ue. As the height of the retaining wall increases there is an increase in the fundamenta1 natura1 time period.