The Standard Installations (Type 1, Type 2, Type 3, and Type 4) are four standard beddings for concrete pipe that reflect the many factors affecting the pipe-soil system. A Type 1 Installation requires the highest level of compaction and the highest quality granular material; a Type 4 Installation requires the lowest level of compaction and lowest quality bedding material.
The Standard Installations were developed through years of investigation and research into the behaviour of concrete pipe in buried conditions. The Standard Installations provide both the designer and the installer with quantifiable, versatile, and conservative soil types and compaction levels for the material used in the installation. These installations facilitate the design of a rational and cost-effective concrete pipe soil system by providing an optimum range of installation characteristics.
American Concrete Pipe Association’s Standard Installations Guideline
American Concrete Pipe Association’s Standard Installation & Bedding Factors for Indirect Design Model