Figure 3. Generalized p'-q plot showing reconsolidation-consolidation stress paths for the cemented and uncemented conditions of a lithologically similar sediment. The cemented condition will have a larger envelope and/or a higher porosity. Its stress path shows a steep rise (higher constrained modulus) to yield, which is not on the K_o line. Yield is followed by reduction of ∆s as cement is destroyed and the yield envelope shrinks to that of the uncemented state. An uncemented sediment with the same yield envelope as the decemented case above has a simple bilinear stress path if the initial stress falls close to the previous unloading path (normally consolidated). If the initial stress is significantly lower than that (an overconsolidated condition), an uncertain stress path, possibly with an incorrect yield, may be measured (see Mesri and Hayat, 1993).