Page 3 - Trench and Excavation

Table of Contents

Table of Contents ......................................................................................................................................................... 3
Glossary of Excavation Terms .................................................................................................................................... 4
CHAPTER 1 - KEY PERSONNEL .......................................................................................................................................... 9
THE COMPETENT PERSON ................................................................................................................................................. 9
THE REGISTERED PROFESSIONAL ENGINEER ....................................................................................................................... 9
THE EMPLOYER ................................................................................................................................................................ 9
THE WORKER ................................................................................................................................................................. 10
CHAPTER 1 REVIEW QUESTIONS ...................................................................................................................................... 11
CHAPTER 2 - SOIL MECHANICS AND CLASSIFICATION ....................................................................................................... 12
FACTORS WHICH HOLD SOIL TOGETHER ........................................................................................................................... 12
INTERNAL FRICTION ......................................................................................................................................................... 12
FACTORS WHICH CAUSE SOIL TO FAIL .............................................................................................................................. 12
CAVE-IN WARNING SIGNS ................................................................................................................................................ 14
SOIL CLASSIFICATION ...................................................................................................................................................... 14
TYPE A SOIL .................................................................................................................................................................. 14
TYPE B SOIL .................................................................................................................................................................. 15
TYPE C SOIL .................................................................................................................................................................. 15
SOIL TESTING ................................................................................................................................................................. 15
CHAPTER 2 REVIEW QUESTIONS ...................................................................................................................................... 18
CHAPTER 3 - PROTECTION SYSTEMS ............................................................................................................................... 19
SHIELDING SYSTEMS ....................................................................................................................................................... 19
SLOPING AND BENCHING SYSTEMS ................................................................................................................................... 20
SHORING SYSTEMS ......................................................................................................................................................... 22
PARTS OF A SHORING SYSTEM ......................................................................................................................................... 23
APPLICABILITY OF OSHA TABLES ..................................................................................................................................... 24
CHAPTER 3 REVIEW QUESTIONS ...................................................................................................................................... 26
CHAPTER 4 - GENERAL REQUIREMENTS AND THE COMPETENT PERSON …………………………………………………..…...27
INSPECTION OF THE TRENCH ............................................................................................................................................ 27
ATMOSPHERIC TESTING ................................................................................................................................................... 27
EMERGENCY EQUIPMENT ................................................................................................................................................. 28
WATER HAZARDS ............................................................................................................................................................ 28
STABILITY OF ADJACENT STRUCTURES .............................................................................................................................. 29
UNDERGROUND INSTALLATIONS ........................................................................................................................................ 29
EXPOSURE TO VEHICULAR TRAFFIC AND BARRICADING ...................................................................................................... 30
EXPOSURE TO FALLING LOADS ......................................................................................................................................... 30
ACCESS AND EGRESS ..................................................................................................................................................... 31
IMPORTANT TRENCH NUMBERS ........................................................................................................................................ 32
CHAPTER 4 REVIEW QUESTIONS ...................................................................................................................................... 34
Appendix A – Trench Protective System Reference Charts ................................................................................... 35

Trench & Excavation
Competent Person Training P3 Safety Solutions LLC
Page 3