Influenced by El Nino,China has experienced a rainfall with big range, high strength and longduration this year, and several places suffered from severe flood disasters. OnAugust 24, the Ministry of Housing and Urban-Rural Development issued the Notification concerning Enhancement of UrbanDrainage and Flood Prevention Ability and Promotion of Construction of UrbanComprehensive Pipe Gallery, requiring that the urban undergroundcomprehensive pipe gallery project should be well planned, the urban drainageand flood prevention and the construction of urban underground comprehensivepipe gallery and sponge city should be simultaneously enhanced, the natural andmanual force, and aboveground and underground construction shall be combined,and the function of “leakage, stagnancy, storage, purification, usage anddrainage” should be displayed.

In Wuhan, one of thecities suffering from the most serious influence due to the heavy rainfall, aleading underground comprehensive pipe gallery project in China invested by OceanwideHoldings has taken shape, providing strong support for the prosperity anddevelopment of the city. A 6.1km-long comprehensive pipe gallery has been builtunder Wuhan CBD as the underground supply line of the city, where municipalpipelines for power, telecommunications and water supply are intensively laid. Thereare numerous trays and stands in the comprehensive pipe gallery for the orderlyarrangement of cables, and adequate space for human work.

On May 24, Li Keqiang,member of the Standing Committee of Political Bureau of the CPC CentralCommittee and Premier of the State Council, investigated Wuhan CBD underground comprehensivepipe gallery. Premier Li Keqiang said that the Chinese cities were full ofhigh-rise buildings with good momentum, but they fell far behind with theadvanced countries in terms of the depth and width of underground space utilization.The underground space was an important part of the city with huge potentialresources, and we should make full use of resources to expand new space andrebuild Wuhan into a new city.

As early as 11 yearsago, Wuhan City began the planning of the construction of CBD undergroundcomprehensive pipe gallery. At the beginning of 2005, Wuhan MunicipalGovernment organized the relevant management department and constructionorganizations of the business district to jointly finish the Special Study of Comprehensive Pipe Galleryin Wangjiadun Business District. Two years later, Wuhan Municipal Planningand Research Institute completed the ComprehensivePipeline Planning of Wangjiadun Business District of Wuhan City.

This is a dream aboutsmart city, and a bold imagination of engineers about the underground spaceutilization: above the comprehensive pipe gallery lies the municipal roads ofCBD; under the comprehensive pipe gallery lies the underground corridor. Theunderground comprehensive pipe gallery is equipped with advanced securitysystem within a scope of 7.41km of Wuhan CBD.

The 6.1km undergroundcomprehensive pipe gallery enjoys the integrated design with the underground trafficcorridor, and the branch line pipe gallery is established in the structuralcavity above the traffic corridor. The underground comprehensive pipe gallerywill become a new artery transfusing blood to Wuhan economy.

In the phase ofplanning, the planning department, design institute and constructionorganization conducted on-site investigation of successful domestic and foreignprojects, and determined the pipeline category and system layout principle ofthe comprehensive pipe gallery in combination with the actual situation ofWuhan CBD. There are three types of pipelines in the comprehensive pipegallery: power pipeline (10KV, 110KV, 220KV), water supply pipeline (with adiameter of less than 600) and information pipeline; system layout principle:integration of direct burial and pipe gallery; consistency between artery pipegallery and power high-voltage trunk circuit lines; and maximum radiation of the central area by thebranch line pipe gallery.

According to theproject requirements of the underground comprehensive pipe gallery, OceanwideHoldings built a tunnel space under Wuhan CBD, integrating various project pipelinesfor power, communication, gas, heat supply, water supply and drainage, etc. Theexpansion, maintenance and renovation of all the pipelines will be conductedwithin the pipe gallery, which can eliminate the excavated urban roads.

The FBG automatic firealarm subsystem is equipped in CBD underground pipe gallery. FBG detector is singlylaid lengthways along the cable tunnel and the single FBG detector has amonitoring distance of 600m. The FBG automatic fire alarm subsystem can monitorthe cable tunnel in different partitions with the wavelength divisionmultiplexing and identical FBG multiplexing mode.

In addition to thefire alarm system, the pipe gallery is also equipped with superfine powderextinguishing system, and each fire compartment includes a set of gas detectorsto detect oxygen, carbon monoxide, methane and sulfuretted hydrogen. When anygas reaches certain concentration, the system can exhaust the air incombination with the draught fans.

The responsible personof the Technology Management Department of Wuhan CBD Company told the reporter thatthe high-pressure cabin has high-voltage cables (110kV, 220kV), and the mainreason for the fire is the overload and short circuit of electric powercircuits. The fire extinguishment with water system will easily lead to shortcircuit. While the superfine powder fire extinguisher can rapidly control andextinguish the fire within about ten seconds with high efficiency, high speed,with no or low toxicity and minor environmental influence, which can apply tothe electrical fire, and guarantee the high-voltage power supply system.

The project hascreated the wonder of Chinese underground project from planning layout,construction to mechanical and electrical installation. Currently, theconstruction of Wuhan CBD underground comprehensive pipe gallery has beenbasically completed, attracting visitors from all over the country.