Changes in Response of Footings Loaded Dynamically in Horizontal Direction due to Tunneling in Soft Soils  Fulltext 

[ Mahmoud Ghazavi ] - Assistant Professor, Civil Engineering Department, Isfahan University of Technology, Isfahan, Iran

خلاصه مقاله:

In urban areas, the construction of shallow tunnels may be under consideration. The presence of such tunnels may adversely affect the response of already-constructed foundations, resulting in changes in machine operations. This paper presents a two-phase analysis for changes in the response of footings due to tunnelling in clayey soils. In the first phase, a newly developed mathematical expression is used to determine the free field movement of the ground in the horizontal direction due to tunnelling. In the second phase, the calculated free field lateral movements are imposed on the footing soil and the response of the footing is calculated under dynamic loads. In the analysis of the footing, for a given dynamic load, the well-known equilibrium equation is established and explicitly solved. It will be shown that, rather than usual parameters affecting footing response such as loading details (like frequency, amplitude, type of loading), footing geometry, footing embedment depth, characteristics of the underneath soil (such as stiffness, damping behaviour, and geotechnical properties) the location of the tunnel relative to the footing placement, tunnel geometry, and ground loss ratio can affect the footing behaviour. The results will be shown graphically.

Settlement, Soft soils, Tunneling, Winkler type analysis, Shallow foundations, Dynamic analysis