This article states the calculation theory of 500 kV compact six split transmission lines balance line scant length and calculation steps and methods,which is attached with reactive examples.

The secant stiffnesseses of frames and anti-earthquate walls at different deformation stages are determined from experimental data.

frames and aseismic walls models, hence, the secant stiffness of frames and aseismic walls at different deformation stages are determined, the composition of lateral displacements of R.

An element tangent stiffness equation was derived based on the secant stiffness equation of stability function elements with shear deformation effects considered.

Determination of effective length of a common pile in deep overlay soil layers with secant rigidity of pile;

Measures are presented to solve the dimension disaster problem:select the control variables by the secant sensitivity method to reduce the dimension of search space;divide the power system into 2 layers and several zones according to the voltage grades and locations and use the cooperative coevolutionary approach to improve the search efficiency and solution quality.