Composite stiffness and biparameter method for analyzing retaining structures of deep foundation pits with internal braces

Composite stiffness principle with biparameter method applied to reasonable calculation of piles subjected to laterally concentrated loads on the top of piles brought forward by Wu Heng-li, is extended to be applied to retaining structures of deep foundation pits subjected to laterally distributed loads (earth pressure). Numerical method of link finite elements is brought forward. Then an engineering example of the construction process of excavation and retaining structures of a deep foundation pit with internal braces is simulated. Reasonable wall-soil composite stiffness and subgrade reaction biparameter are back-analyzed by displacement measurements. Compared with the existing methods, the results obtained by this method are closer to the measurements. So it is shown that numerical solutions of link finite elements based on composite stiffness and biparameter method can be more reliable to calculate retaining structures of deep foundation pits with internal braces; and it has the reference value for applications.