underground structure.ppt

Reasons for cracks formation Reasons for cracks formation Main reason : The dry and cold shrinkage of the concrete(混凝土干缩和冷缩) Different hydration heat(水化热) of cement variety.If hydration heat is high and large temperature difference between the environment and the environment,The cracks will appear. Cold joints and horizontal construction joints.(冷缝与水平施工缝)Cold joints is due to the flow of concrete is too long and not timely coverage of the new concrete, resulting in the lower concrete has been set, the upper part of the new concrete is not on the ground and the emergence of leakage through the gap. Improper maintenance(养护不当) Concrete curing time is not enough Human factors Questions 1.What kinds of underground construction according to the construction method can be divided into? Ming dig and underground 2.What is the main reason for crack formation? The dry and cold shrinkage of the concrete 3.What are architectural design requirements? Good engineering geological and hydrogeological conditions The necessary protection Appropriate internal environment Favorable conditions for the structure design and construction Company Logo LOGO * underground structure Name：李菁 Student ID：154812262 Abstract Definition History Classification Archiectural design requirements Advantages and Disadvantages Environmental protection measures Reasons for cracks formation Definition:built in rock or soil . It is the product of modern urban development, moderate city contradictions, improve the living environment of the role, also opens up a new life for mankind. Definition History Cave Mine,highway tunnel,railway tunnel Military facilities,warehouse Highway transportation network, underground street, underground commerical centre Ancient times, humans began to use natural cave through prevention, shelter, and to avoid the beast.The plateau area of northwest China, cave of the tradition continues to this day After indus