To obtain a seismic design method for underground structures

which has simple model with higher accuracy and can better reflect the soil-structure interaction

this paper presents a modified response displacement method. The two-parameter foundation model was adopted to simplify the soil

which is closer to the soil properties than the traditional single-parameter foundation model. Based on the force and deformation properties

the two-parameter computational model was simplified

and the modified response displacement method was obtained

which considers soil-structure interaction. Compared with the traditional model

the proposed model only modifies the foundation bed coefficient of normal spring

making it still a simple computational model. In addition

a numerical model was established to verify the correctness of the modified method and compared with the traditional response displacement method based on the results of dynamic time-history calculation. Results show that the error of the modified method could be reduced by half compared with the traditional response displacement method. Therefore

the proposed method has simple model and high computational accuracy

which can be applied in the seismic design of underground structures.