Experimental investigation of soil–structure interface behaviour under monotonic and cyclic thermal loading

Abstract The effect of temperature on the monotonic and cyclic shearing response a soil–structure interface is critical importance for application thermal-active geo-structures. To investigate this, soils soil–concrete interfaces were comprehensively tested with temperature-controlled direct shear device under both fixed temperatures thermal/mechanical cycles within range 2–38 °C. Monotonic various boundary conditions, including constant normal load (CNL), stiffness (CNS) volume (CV), conducted to resemble conditions that thermal-active-geo-structures may experience. strength properties sand, clay, sand–concrete clay–concrete partially influenced by heating cooling all conditions. However, several effects observed which could affect performance thermo-active structures. Heating caused be overconsolidated, implying lower excess pore pressure would generated during shearing. CNS tests suggested degrade due (thermally induced) displacements, this strongly related state soil rather than directly. In these tests, medium-dense degraded almost zero after 5 cycles, whereas asymptotically around 60% its 10 cycles.