1. PowerChina Huadong Engineering Corporation Limited , Hangzhou, Zhejiang , , China .
2. Zhejiang Huadong Mapping and Engineering Safety Technology Corporation Limited , Hangzhou, Zhejiang , , China .
3. Zhejiang Huadong Geotechnical Investigation & Design Institute Corporation Limited , Hangzhou, Zhejiang , , China .
4. Beijing Zhongguancun Insititute of Ssfety Science Corporation Limited , Beijing , , China .