Abstract:

The safety level of deep foundation pit construction of metro station is difficult to determine due to the fuzzy evaluation index, grayness and expert cognition extremes. As a result, a safety evaluation method for deep foundation pit construction of metro station based on IOWA operator is proposed. Firstly, the two dimensions of WBSRBS are coupled to construct the index system from six aspects, i.e. seepage damage, inrush damage, mechanical injury, soil landslide, support instability and kicking damage. Secondly, the expert initial decision data are reordered; the IOWA is utilized to determine the initial weight of the indicator, and the coefficient is introduced to adjust the boundary weight, so as to obtain the final weight of the indicator. Thirdly, the gray clustering is used to improve the transparency of the evaluation process, and the safety level of the deep foundation pit construction is analyzed. Finally, the evaluation method is applied to Zijingshan Station on Zhengzhou Metro Line No. 1; and the applicable results show that the construction safety level of deep foundation pit of Zijingshan Station is high, and the seepage failure, soil landslide, support instability and kicking damage are the main risks affecting the construction safety of deep foundation pit, which should be paid more attention to.

Key words: metro station, deep foundation pit, safety evaluation, IOWA, grey clustering