Abstract
There are some statistical models on the strength of brittle materials such as rock and concrete. Weakest link model or bundle model is a representative one. Scale effect on the strength of cement-treated soils is studied theoretically using a new statistical model in which the weakest link model and the bundle model are combined. The proposed combined model is represented by a function with variables of diameter, height and coefficient of variance of the specimens. This model expresses not only the difference in volume of the specimens but also the differences in diameter and height, individually. In order to confirm the validity of this model, the unconfined compression and undrained triaxial tests are performed on the cement-treated soils in different sizes. The combined model is compared with the laboratory test results of the treated soils and the previous results of model mixing test with different mixing level. The validity of this model is also confirmed by comparing with test results on large size specimens sampled from the improved soil columns by Deep Mixing Method. The average strength of cement-treated soils in different sizes is predicted from the average strength and coefficient of variance of specimen in standard size.
