Abstract：Cavity expansion theory have been widely used in geotechnical engineering problem as a mature theory tool. However, it is not applicable to the elliptical cavity expansion problem. Based on the conformal mapping method, the outer region of the initial elliptical cavity on the physical plane is mapped to the outer region of unit circle on the phase plane, and the displacement caused by the elliptical cavity expansion on the physical plane is transformed to the phase plane. The elastic solution of elliptical cavity expansion is presented by plane complex variable elasticity method. This degeneration solution of elliptical cavity is compared with the conventional circular cavity expansion and the reliability of the elliptical cavity expansion elastic solutions is verified. Then, the elastic mechanics characteristics of the elliptical cavity expansionare analyzed by application of an example. The results show that the degeneration solution of elliptical cavityis in agreement with the conventional cavity expansion elastic solution. It is more difficult to expand in the semi-major direction rather than semi-minor and the required expand pressure in the semi-major direction is larger than that in the semi-minor direction. In addition, when the expansion ratea2/a1=0.11/0.1=1.1, the effect radius of expansion equals to the 10 times of the cavity radius.
2015, Vol. 36 
