Spring Method According to JGJ 120-2012
This method is used for analysis of sheeting structures and it is based on the Chinese standard JGJ 120-2012 (Technical specification for retaining and protection of building foundation excavations). In principle, this theory is similar to calculation according to the method of dependent pressures, the difference is in consideration of earth pressures. The following figure shows that behind the wall (outside of the foundation pit) acts active earth pressure pa or earth pressure at rest p0 (it's defined in the "Settings" frame).
In front of the wall there are considered springs (defined by using the modulus of subsoil reaction), which models reaction of the soil in a horizontal direction. In case of the attainment of ultimate pressures a limiting of the size of springs is the same as for method of dependent pressures.
Principle of spring method acording to JGJ 120-2012 for solution of sheeting structures - (a) non-anchored structure, (b) anchored or strutted structure
JGJ 120-2012 (Technical specification for retaining and protection of building foundation excavations).