Designs are dependent on project specifications and applications. Lateral earth loads from soil and hydrostatic loads from ground water. Vertical loads from the cover soil and live loads above. Surcharge loads from nearby impact loads. Seismic loads where applicable. After determining the size and design parameters required the appropriate ISO standards are used to provide the most economical design.
Medium Duty: Designed for lateral earth pressure and hydrostatic loads from ground water, live load supercharge and adjacent vehicular traffic.
Heavy Duty: Designed for lateral earth pressure and hydrostatic loads from ground water, live load supercharge and direct heavy vehicular loading.