AN INVESTIGATION ON OF FOUNDATION INPUT MOTION IMPOSED ON A SURFACE STRIP FOUNDATION CONSIDERING PROXIMITY TO AN EMBEDDED STRIP FOUNDATION

Soil-structure interaction is an emerging issue in seismicdesign of structures. According to the history ofthe eld, this phenomenon is usually studied in two sequentialparts, i.e., kinematic,inertial interactions.Kinematic interaction causes the dierence of free eldmotion,foundation input motion in the absence ofmasses of super structure,its foundation. Filteringthe system input motions is the most crucial characteristicof this part of the problem. In the literatureon Kinematic interaction, however, most of researchershave focused on single foundation. In addition, few studiescan be found on adjacent foundations with semicylindercross- section under plane SH wave. While everybuilding, located in urban area, is commonly surroundedby various structures. It causes the adjacencyof foundations inevitable. Hence, it would be importantto investigate the ways to include the eects ofnearby foundations on input motions. The existenceof neighbor foundations may physically be interpretedas constraints in mathematical equations. In this work,the proximity eect of two strip foundations on foundationinput motion is investigated. The free eld motionis considered as vertical propagating SV waves withjust translational movement at the surface. Various embedmentdepths,dierent proximity distances betweenfoundations are studied. The simulation is doneby ABAQUS software,the analysis is performed inthree stages. First, the changes in time history of a samplerecord through a class of adjacency conditions wereexplored. Then, frequency domain aspects of proximityeect were investigated. In the third,nal steps,spectral aspects of this phenomenon were examined forthe same class of adjacency conditions. The results arepresented in non-dimensional format. The main deductionis that for a surface foundation, adjacency to anembedded foundation causes rocking,vertical inputmotions. Meanwhile, the translational movement is adjustedtoo. This adjustment would intensify or diminishthe free eld translational motion in dierent frequencyranges.