Study on Combined Toe-and-side Grouting Technology for Over-length Friction Piles

Combined toe-and-side grouting technology was employed to increase the bearing capacity of cast-in-situ bored piles. A field test was conducted to investigate the combined toe-and-side grouting technology for over-length friction piles. L-shaped injection pipe was used for pile-toe grouting and circular injection pipe was designed for pile-side grouting. The design and setting of the injection pipes was introduced in detail for reference. And, the construction process and the selection and computation of grouting pressure and volume were investigated. The grouting devices and grouting parameters was proposed for combined toe-and-side grouting on over-length friction piles. The principles and standards for grouting control were also summarized to provide a good reference for post-grouting construction of over-length friction piles.