With the installation of absorb pipes in the underground structures such as retaining structures of foundation pit,piles,bottom slabs,shield tunnels,or tunnels constructed by New Austrian Tunneling method,an energy geothermal engineering,a new kind of system for geothermal energy exploitation,is established.Firstly,this paper presents a new conception of energy geotechnical engineering.After a comprehensive analysis of advantages and disadvantages of various techniques for geothermal energy exploitation and...