Review: Soils & Excavations

Cohesive Soils

Stick together, plastic when moist, can be excavated with vertical side slopes.

Noncohesive Soils

Lack stickiness.

Bearing Capacity

Crucial for foundation design; low-capacity soils may require specialized systems, such as post-tensioned slabs.

Critical First Steps

Comprehensive site investigation and geotechnical reports assess soil conditions and potential hazards.

Backfill Quality

Building codes mandate excavation backfill to be free of organic material and debris to prevent future settlement or instability.

Efficient Practices

Rely on appropriate equipment like backhoes, designed to dig below the ground surface.

OSHA Excavation Standard

All open excavations are subject to this standard, providing a safety framework based on soil classification and site conditions.

SOE Systems

Vital for retaining soil and ensuring stability.

OSHA Protocols

Strict; excavation below a shield is permitted only if engineered to resist calculated forces, emphasizing planning safety.

Function

Foundations transfer structural loads to the earth.

Spread Footings

For wide load distribution.

Piles and Piers

Deep foundations for sites with low surface bearing capacity.

Post-Tensioned Slabs

Often used on challenging ground like expansive soils.

Waterproofing

Defends against liquid water and hydrostatic pressure.

Dampproofing

Manages soil moisture and water vapor, preventing capillary action and protecting against dampness and mold.

Vapor Barrier

A key component of moisture control.

Function

Provide structural integrity by resisting lateral earth pressure.

Monolithic Poured Concrete Walls

Known for strength and water resistance.

Concrete Masonry Unit (CMU) Block Walls

Versatile, often reinforced with steel for stability.

Purpose

Manage subsurface water by collecting and diverting groundwater to relieve pressure on foundation walls.

Perimeter Drains (French drains)

Intercept water.

Sump Pits with Pumps

Actively eject collected water away from the building.