2.1 The Continuous Exploration of Foundation Treat...
First of all,geological surveys were required.In the earlier period,China served mainly for water conservancy projects,railway projects and urban water supply construction.In the later period,it focused on environmental geology and disasters.Geological survey is a breakthrough in the third-front construction.
Guangming Chemical Plant in northwest China's Datong County,Qinghai Province was a confidential enterprise that produced heavy hydrogen water for hydrogen bombs,which was owned by the Ministry of Chemical Industry during the 1960s-1980s.It was put into production in 1969.In order to cooperate with hydrogeological and engineering geological surveys,the geophysical exploration professionals used electric profiling methods to detect strata and search for fault zones,solved the landslide problem of the plant finally.Guangming Chemical Plant completed the 1∶500 geological survey reports in May 1965,providing a reliable geological data in time.The site selection of the plant took into account the following factors:①The exclusion of geological landslides.②Adjacent to Qinghai Atomic test site in Haishu,Qinghai Province,when heavy water already had the conditions for specific train transportation.③The site was close to the high-quality water source necessary for heavy water production.④The mountains nearby could be used to store heavy water in caverns,which conformed to the layout principles of the third-front construction.⑤The built coal mines plant and other power plants were able to provide energy.(https://www.daowen.com)
Secondly the construction of collapsible loess needs to consider antifreezing,moisture-proof and mechanical shock.Guangming Chemical Plant is a model of fine construction too.Based on the“653/151 Hydrogen and Oxygen Storage Room”design specification in the historical drawings,we can look through that strict experiments and on-site operations,“The foundation of the wall,the foundation of the indoor equipment and the trenches must be layered and compacted on the original soil compaction layer for 300mm,the dry weight of the soil shall not be less than 16t/m3.All solid soil backfilling shall not use hard clay blocks or organic matter,etc.,with intermixed brick and sandstone frozen soil and shall be made of prime soil under the bulk water slope meanwhile shall be 300mm wider than the bulk water slope.The backfill soil for the ping and foundation pits must be compacted manually and require a dry capacity weight of 1.6 t/m3.”[3]Such wide-ranging topics ensure that the heavy water plant is both cultural heritage and durable historic building groups today.Unfortunately the plant has been vacant due to bankruptcy since 1998.