Abstract：Methods such as numerical simulation and experience function imitated and so on were adopted to study on time-space effect of deep foundation pit. Because of complexity in influence factors and difficulty in measure of various factors，normal analysis methods were not strong in adaptability. At present，only time or space effect was considered in analysis of time-space effect，and analysis method of time-space effect considered simultaneously based on artificial intelligence was not established. It is shown that high non-linear complex problems can be solved easily by artificial neural network as well as the method of ANN(artificial neural network) based on GA(genetic arithmetic) has optimizing function in the whole field of solution. The structure and weight value of the network are optimized in-phrase in GA-ANN model，and the weight value of the network and influence factors of problem are two kinds of different qualities. When the two kinds of variables are regarded as input variables to train the network，it may lead to chaos of the network，thus it will decrease identification precision of the network. The model of time-space effect on deep foundation pit is established that the structure and weight value of the network can be optimized by stages with GA based on labor of influence factors. The comparative analysis with the BP(back propagation) model and the GA-ANN model optimized in-phrase shows the model optimized by stages can improve identification precision and analysis efficiency of the network，thus it will be closer to the fact.
