Application of sand-rubber mixtures to mitigate vibration and ground shock
Chew, Jia Han
Date of Issue2018-11-12
School of Civil and Environmental Engineering
With the rapid increase in population density in urban cities, it is inevitable that vibrations levels due to myriad of reasons will be higher. Coupled with increased risk of terrorism, there is a need to mitigate ground vibrations caused by man-made ground shock from possible acts of terrorism. One of the most effective ways of reducing ground vibration caused by man-made activities is to introduce a seismic wave barrier between the source and the area of interest. Besides hardening an underground structure, it is possible to use a seismic wave barrier to mitigate ground shock pressure on the structure. The objective of this research is to study the responses of sand-rubber mixtures (SRM) as a seismic wave barrier to vibration and ground shock. Characterisation of SRM using laboratory tests were performed. Two separate series of small-scale field tests were performed. The first series involves using SRMs and open trench as seismic wave barrier against surface waves complemented with numerical simulations using LS-DYNA. Dimensionless amplitude ratio (Ar) contour plots were developed for use as a preliminary guide in implementation of seismic wave barrier on site. The second series involves using SRM to protect underground structure against ground shock caused by buried explosions. The field tests were modelled in LS-DYNA. The finite element model in LS-DYNA was verified to be able to correctly simulate underground explosions. The finite element model was able to replicate the field test results. In additions, the effect of density ratio between soil and structure on the peak incident pressure was examined through numerical modelling.