Pile and beam construction is generally applied in high-risk buildings where external damage is both significant and progressive. Unlike ground improvement, the system can be proven by design and/or testing. Micropiles, unlike screwpiles or displacement piles, can provide enough loadings in any ground conditions due to its ability to penetrate boulders and bedrock. In many instances, our design may be purely based on the length of rock socket.
This system uses micropiles to support short needle beams installed transversely through the rising walls or beneath the foundation. The two most common configurations are straddle beams and cantilever beams. Straddle beams are formed on two micropiles supporting a needle on either side of the wall or at adjacent corners with both micropiles under compression. Cantilever beams are formed by a pair of micropiles that support a needle entering the wall from one side, usually externally; the micropile closest to the wall is under compression whilst that furthest is under tension.
As micropiles are passive installations, it will always take time for the micropile to begin to mobilise (or work). Therefore, a settlement period should be allowed before any superstructure repair works are completed. In very rare cases, the specification may require a more active solution due to time constraints or client requirements. In this instance, we can post tension cantilever beams to allow superstructure repair works to commence immediately