QAQC in Construction

Soil types The type of soil determines the strength and stability of trench walls. Identifying soil types requires knowledge, skill, and experience. Even hard soil may contain faults in seams or layers that make it unstable when excavated. The foreman or supervisor must be knowledgeable about soil types found on a project and plan protection accordingly. This knowledge must include an awareness that soil types and conditions can change over very short distances. It is not unusual for soil to change completely within 50 metres or for soil to become saturated with moisture over even smaller distances. The Construction Regulation sets out four soil types. If you are unsure about the soil type, have the soil tested to confirm the type. Type 1 — It is hard to drive a pick into Type 1 soil. Hence, it is often described as “hard ground to dig”. In fact, the material is so hard, it is close to rock. When excavated, the sides of the excavation appear smooth and shiny. The sides will remain...

(a) Scope and application - (1) Scope. This appendix describes a method of classifying soil and rock deposits based on site and environmental conditions, and on the structure and composition of the earth deposits. The appendix contains definitions, sets forth requirements, and describes acceptable visual and manual tests for use in classifying soils. (2) Application. This appendix applies when a sloping or benching system is designed in accordance with the requirements set forth in 1926.652(b)(2) as a method of protection for employees from cave-ins. This appendix also applies when timber shoring for excavations is designed as a method of protection from cave-ins in accordance with appendix C to subpart P of part 1926, and when aluminum hydraulic shoring is designed in accordance with appendix D. This Appendix also applies if other protective systems are designed and selected for use from data prepared in accordance with the requirements set forth in 1926.652(c), and the use of t...

I. Introduction Excavating is recognized as one of the most hazardous construction operations. OSHA recently revised Subpart P,  Excavations , of  29 CFR 1926.650 ,  29 CFR 1926.651 , and  29 CFR 1926.652  to make the standard easier to understand, permit the use of performance criteria where possible, and provide construction employers with options when classifying soil and selecting employee protection methods. This chapter is intended to assist  OSHA Technical Manual  users, safety and health consultants, OSHA field staff, and others in the recognition of trenching and shoring hazards and their prevention. II. Definitions A. Accepted Engineering Practices  are procedures compatible with the standards of practice required of a registered professional engineer. B. Adjacent Structures Stability  refers to the stability of the foundation(s) of adjacent structures whose location may create surcharges, changes in soil condition...