Abstract: With the development of urban city scale, more and more refuse soil land is used to conduct engineering construction. Since the refuse soil has the characteristics of high compressibility, biodegradability, and fiber reinforcement, geotechnical engineering such as the cone penetration test, pressure-meter tests, static pile, etc., will meet new challenges in this kind of site. Based on the modified Cam-clay model with fibrous reinforce considered and large deformation theory, through introducing an auxiliary variable, the cavity expansion issue is transformed to solve a set of first-order differential equations with given boundary conditions. The modified Cam-clay model is used to verify the accuracy of this research. Then the effect of over consolidation ration and fiber content to the solution is studied systemically. The results show that the refuse soil has a larger plastic radius compared with clay soil. With the increase of over consolidation ratio and fiber content, the inter cavity pressure and plastic radius show an increasing and decreasing tendency, respectively. After elastic and plastic stage, the refuse soil element with different fiber content reaches nearby the critical state of the paste component.

Key words: refuse soil, cylindrical cavity expansion, elasto-plastic solution, fiber content, over consolidation ration