Pile cap extension of a Bridge Abutment

[Useeeer]

We are currently working on a proposal. Following is the overall scope

1. The Pilecap (PC) supports the bearing from a bridge spanning across a navigation channel
2. The PC is supported on ground with continuous sheet pile at front for retaining the soil and fill behind and few rear piles
3. Front sheet pile is corroded over period of time.
4. Scope is to build a new sheet pile in front and integrate it with existing PC

Advice is needed with respect to the integration part with existing PC

The bearings are at 6m spacing. Question in can I consider the bearing load as UDL (considering 45-degree dispersion) between the new and box pile) to arrive at the design forces at interface (middle pile is assumed to be non-existent after some years). I'm worried about the dispersion since the bearing is just before the interface.

Without dispersion the shear is around 140T and the post installed anchors are not viable. Also, the gap between new and old pile will be filled with concrete.. will that contribute in load distribution?

 

[HTURKAK]

You did not provide a lot of info. here and it is hard to visualize the problem at least for me .
My preliminary points are ,

- The continuous sheet pile at front should be anchored and probably anchorage system also corroded ,
- The rear old box pile loads will totally change if the front sheet pile fully corroded ,
- Dispersion of load btw new sheet pile and existing box piles could be calculated assuming rigid abutment and pile cap .

In order to get better responds , pls provide more info and installation method of new sheet pile wall.