Abstract: Compressive modulus Es is one of the physical and mechanical indices of the soil, and is also an important index in the foundation settlement estimation. In the consolidation test, it is difficult to minimize the measurement error of the applied pressure and deformation test indices. On the basis of establishing the spline function of test data (p, ln(h)) and applying the theory of error transmission, the error transmission of the measurement error of test index (p, h) to the compressive modulus is analyzed. The results show that the measurement error of the applied pressure and the deformation test index do not have significant effect on the error transmission of the compressive modulus, and its contribution to the error of compressive modulus are almost the same. The overall transmission error is generally less than 3%. Secondly, the ratio coefficient β>1 of the secant compressive modulus is less than 1.1 for the normal cohesive soil and 1.5～1.7 for the soft soil. The secant compressive modulus of the engineering strain is only suitable for the small deformation. When the tested modulus is applied to the settlement estimation of the soft soil with large deformation, the settlement is much smaller, which needs special attention. The results suggest that the secant compressive modulus determined by the true strain should be used in the revision of geotechnical test code.

Key words: Soil Samples, Consolidation Tests, Compressive Modulus, Transmission Error, Analysis