ABSTRACT
Urban lifelines benefit, circumscribe, and substitute mutually, and coexist nearby, when earthquake occurs, these lifelines will interact and affect each other on disaster. The research on urban lifelines earthquake disaster during the Tangshan earthquake in China, the Northridge earthquake in USA, and the Hyogoken-Nanbu earthquake in Japan shows that lifelines affect structures and functions mutually, form recovery obstacles for each other and lead to second disaster. According to fact lifelines disaster in many earthquakes, a figure showing how lifelines affect each other is made. Based on this figure, the concept of effects degree, meaning how greatly one lifeline affect others, and calculation formulas, are put forward. According to calculation result, the sequence of effect degree is: Yd>Yj>Yt>Ys=Yp>Ym. The sequence of lifeline effects degrees and the time sequence of post-quake recovery are well accordant.
