The various structural members are constructed to minimize ground movements in the vicinity. However, wall cannot be infinitely rigid. Irrespective of placing of struts, diaphragm wall movement cannot be prevented. After some excavation is done, before a strut is placed there is a certain movement of the wall. Also, between subsequent placing of struts certain movement of wall occurs. As a result, the ground movement occurs locally.
If the joints are subjected to such movements excessive forces may generate leading to the distress of the structure. Therefore whatever ground movement occurs, it has to be limited to a minimum value. Total ground movement is the sum total of the ground movement and the bottom heaving. The idea of proving structural members is to minimize ground movements. More rigid the structure, lesser is the ground movement.
Peck (1969) proposed a graph which indicated the ground movements and their extent for a excavation site and site conditions as shown in figure
