The focus of this paper is directed towards investigating the influence of multiple freeze-thaw (FT) cycles on the stress-strain relationships during undrained shearing for an expansive soil under a wide range of confining stresses (σc) from 0 to 300 kPa. Different numbers of FT cycles were applied to compacted specimens. The influence of FT cycles on the soil’s structure was investigated using mercury intrusion porosimetry (MIP) and scanning electron microscope (SEM) tests. FT impacted specimens were subjected to consolidated undrained (CU) shear tests with pore pressure measurement (σc = 10 to 300 kPa) and unconfined compression (UC) tests (σc = 0 kPa) to derive the shearing stress-strain relationships and the associated mechanical properties including (i) failure strength (qu), elastic modulus (Eu), effective and apparent cohesion (c’ and c), and effective and apparent friction angle (ϕ’ and ϕ) obtained from CU tests and (ii) qu and reloading modulus (E1%) and stress (Su1%) at 1% strain obtained from UC tests. Testing results show that FT cycles mainly influence the soil’s macropores with diameters between 5 and 250 microns. Cracks develop during FT cycles and result in slight swelling which contributes to an increase in the global volume of the soil specimens. There is a significant reduction in the investigated mechanical properties after FT cycles. They typically achieve equilibrium after about 6 cycles. The shearing stress-strain curves transits from strain-softening to strain-hardening as the confining stress increases. An empirical model is developed to describe the strain-softening behavior of the specimens under low confining stresses. The model is simple to use and well describes all stress-strain curves obtained in this study that show strain-softening characteristics.