Behavior of a sand-polyacrilate mixture for seismic isolation

Seismic isolation with traditional grouting is hardly effective. Recent results have shown that if a soft grout is used and a continuous barrier having a very low dynamic impedance is created, seismic isolation can be very effective. However, a soft, continuous barrier can cause undesired settlements of existing structures. This paper shows that, considering the barrier made of a mixture of soil and grout made using a Super Absorbing Polymer (SAP), desired values of dynamic impedance can be reached without causing any damage to existing structures. The paper reports also the results of some laboratory tests on SAP-sand specimens at different percentages of SAP, difficult to carry out because of the enormous deformability of the mixture.