Effect of in-soil temperature on pullout failure resistance of single polymeric strap reinforcement

Abstract

The correct design of reinforced soil structures (RSS) must include internal and external stability verifications. For internal stability, verifications include reinforcement rupture, connection rupture, and pullout failure. The present work focuses on pullout failure. RSS can be built with extensible (i.e., polymeric) or inextensible (i.e., steel) materials, each with their own advantages and disadvantages. In the case of polymeric materials, their rate-dependent response is well known and documented, hence, resisting properties (e.g., ultimate tensile strength), must be determined at controlled load- or strain-rates, temperature, and relative humidity conditions. The paper summarizes the results of several pullout box test series carried out on polymeric straps composed of polyester yarns encased in high density polyethylene sheaths with a rough, continuous surface. Grade 30 (i.e., UTS = 30 kN/strap) reinforcement specimens were subjected to pullout forces under different confining pressures and in-soil temperatures using a large steel pullout box combined with infrared heating elements. Simulated embedded depths of 0.5-, 3-, and 7-m were tested. In-soil temperature values ranged, roughly, from 15ºC to 35ºC. Test results include pullout force values along with head- and tail-end displacements. Results show no significant difference in overall pullout capacity for the above mention temperature ranges. On the other hand, increased temperature showed minor increments of pullout displacements (i.e., more ductile response).

The authors wish to acknowledge the support of GECO Industrial (Korea, Rep), VSL Construction Systems (Spain), the Department of Civil and Environmental Engineering (DECA) of Universitat Politècnica de Catalunya·BarcelonaTech (UPC), and the International Centre for Numerical Methods in Engineering (CIMNE).

Peer Reviewed

Postprint (published version)