| |
Excavations which are laterally supported are Braced cuts (Fig-6.6.1-a). The vertical sides of the excavations are supported by a sheeting and bracing system. It consists of relatively flexible sheeting placed against excavations walls. The lateral thrust on the sheeting is resisted by the horizontal members in compression (struts).Known as Bracing system. Bracing is provided as the excavation proceeds and the face of the sheeting becomes exposed. So, various types of the Bracing systems is adopted to make the excavation stable When no plenty space is available for excavation in a natural slopes. Sheet piling is used primarily as a bulkhead to hold or restrict the lateral movement behind it. Some typical uses of Braced Excavation are |
 |
Laying underground pipeline |
|
Construction of bridge abutment. |
|
Construction of basement. |
|
Metro railway construction. |
|
Construction of subway tunnel. |
| |
A Gravity Retaining wall is a Permanent Structure, used, when an excavation is permanent. But when excavation is temporary i.e. excavation for buildings or subway, the excavation is filled with a structure which then permanently retain surrounding soil/earth. If the temporary Excavation is made in sand, the walls of the excavation must be supported during construction of the building by a system of bracing. |
