How many models of metal shoring exist?

The correct answer is that there are two primary models of metal shoring. These models are designed to provide stability and support during construction activities, particularly in trenching and excavation work to prevent collapses. The two models can be classified as:

1. Primary shoring - This is used as the first line of defense against soil collapse. It is typically designed to support the load of the surrounding earth and any additional forces imposed during construction.

2. Secondary shoring - This is an additional support system that may be used when more stability is required, often placed alongside or beneath primary shoring. It enhances the safety and integrity of the structures being supported.

Understanding this distinction is important for safe construction practices and ensuring compliance with safety regulations. Knowing that there are two key models helps practitioners select the appropriate type of shoring based on specific site conditions and project requirements.