A well-designed pile foundation is usually preferred on riverbanks where roads are built. Pile foundations are usually composed of steel, concrete, timber, or a combination of these materials. The piles are driven into the soil until the desired depth is reached, and then the soil around the piles is compacted and reinforced with a concrete cap or other reinforcement to ensure a stable platform for the road. Pile foundations are especially advantageous for riverbanks since they are designed to handle additional loads from the water and sediment, and are also more resistant to movement due to flooding.

Pilings are a useful method in the right circumstances. It is often useful to have review of situation my geologist, engineer, soil scientist and sometimes hydrologist. Pilings may not work to well in skeletal or bouldery conditions, or shallow bedrock. Professionals can help identify unstable materials or soils, and work to avoid excess road drainage into unstable materials. Some stream types are more stable than others, and conditions where excess debris, sediment loading or scouring activity may deserve special measures when locating roads. Reduction in scour along streams can sometimes be done with cross vanes, J hooks, groins or other deflectors. Driving piles into plastic unstable soils may not achieve the desired results due to vibrations. Wet weather restrictions or road closures especially with heavy equipment use may reduce some of the vibrations that can help liquify some soils. Internal drainage of unstable soils and removing any sources of excess water may help. The placement of drop rock to boulder sized materials can sometimes be used to shore up unstable slopes. Assessing road or road section relocations is sometimes appropriate by professionals.

Peter and William

Thanks very much for providing answers.

Much appreciated.

Best regards

Ravi