Figure 4-25. - Position of walers before placing sheetpiling for shoring trenches.

Figure 4-27. - Method of bracing when two lengths of sheetpiling are used.

Figure 4-26. - Trench shoring with trench jacks for cross braces.

2. Bracing or shoring of trenches should be carried along with the excavation.

3. Cross braces or trench jacks should be placed in a true horizontal position, secured to revent sliding, falling, or kickouts.

4. Portable trench boxes, sliding trench boxes, or shields should be designed, constructed, and maintained

Figure 4-28. - Bracing with jack screws in hard soil.