1988: June 12-15, the 14 th ITA general assembly and Tunnel & water science seminar were held in Madrid, capital of Spain. Professor Gao Juqing, vice president of CCES tunneling and underground works branch, ITA executive council member participated in the occasion. In this assembly, new executive council of ITA was elected, of which professor Gao Juqing was elected as a member of the new ITA executive council. 
 　　Oct. 8-12, the 5 th CCES-TUWB congress and the 7 th academic exchange conference of metro specialty committee were held in Nanjing. 289 representatives attended the conference, and 146 papers were presented, and 12 papers were selected as excellent papers. 
 　　 1990: Sep. 3-7, the 16 th ITA general assembly and International Tunnel & Underground Works Seminar were held in Chengdu. This assembly was sponsored by CCES and ITA, and organized by Southwest Jiaotong University and CCES-TUWB. More than 170 experts in tunneling field from 28 countries and regions, including ITA president Koukeland, vice president, executive council members, and 310 representatives from China attended the conference. The subject of the event is “the current status and future of tunnel and underground works”. In the event, experience and technical achievement in the aspects of railway tunnel, road tunnel, and hydraulic tunnel and underground space utilization were discussed. Totally 152 papers, which were compiled and published in 3 volumes of paper collection, were selected and presented in the event. 
 　　 Sep. 8, the 3 rd council conference of CCES-TUWB was held in Chengdu. More than 80 persons from the 2 nd council and 3 rd council attended at the conference. The 3 rd council consisted of 68 members. In leading members of the 3 rd council were selected by the council members attending the conference.