Basement

[netix]

We need to install a water proof basement under an existing buildings wall, probably using structural steel frame:

natural clay becoming firmer with depth at 7 ft from ground level

Objective is to avoid having to shore up the walls, if possible.

Has any one experience of the following method

1. placing a pillar outside and at each end of a wall
2. inserting girder connecting pillars
3. internal support pillars where necessary
4. do this for all walls to create supporting structural load baring frame

Are there alternatives?

Jon
Netix4@yahoo.com

 

[ishvaaag]

This reform work is in general highly complicated. Of course men have done reforms of any kind to their buildings. The question is so complex that without any doubt requires a competent structural designer (and a prudent contractor) well acquainted with the extant building structure and then with what is going to be made, and through what means.

The main factor in your question, as much the whole plan of the building is to be got alift in new support, is to ensure that all the hard points (assume there are) of your pre-existent structure at foundation level are to be supported in paulatine way that does not cause any distortion that damages the extant building. This simplifies where part of the plan is not be voided and does not require new support, or can have it from supplemental foundation under the hard point.

So in general for this kind of works

1) you build new foundations able for all loads

2) you transfer by press and/ or partial support but always in checked way all the extant loads to new items (columns, beams) supported in the new foundations, all stiff enough as to that no damage results in following step which is

3) separate your extant building from the old foundations by cutting from them or the old foundations elimination. Some settlement unavoidably will occur for the new items take the load, but everything must be designed for the deformations be kept small.

4) then (if well thought when planning the scheme of the new foundations) you will start or complete -some items can be part of the already built structural system- your intendend work, damp-proofing included.

The complexity of the works make them expensive, and these things are only made for valuable buildings, much appreciated, when obliged by use or concurrent property, or for technical ability display.