Soldier pile wall next to existing structure 3

[milkshakelake]

I'm designing a 14' deep basement wall next to a 3 story brick building. The adjacent building is 4' away and its footing is 5' deep so there is a surcharge. The peak of the surcharge would be about 8' to 9' below grade in my estimation.

Normally, I use a tangent or secant pile wall when there's a building surcharge. However, is it acceptable to use a soldier pile wall with wood lagging? If there is backpack or grout between wood lagging, maybe there won't be soil loss through the gaps. The soil is about 6' of fill and then silty sand with traces of rock. A weird idea I was thinking was to use steel plates instead of wood lagging up to the peak surcharge point to minimize the number of gaps.

The reason I'm considering soldier pile wall is because the next door building is relatively small and this project is too small to justify a tangent pile wall (5 stories, 40'x100' lot).

 

[oldestguy]

When evaluating the posts shown above, take a look at the experience of the advisors. Unuff said. Some likely is very bad.

If you want to be sent to the loony bin, wrap the pile with felt paper.

 

[milkshakelake]

Thanks for all of your input. I considered all the options and I've been pondering this for days. In the end, since this is such a headache, I decided to design a stepped footing and lose cellar space instead of dealing with shoring. The 1:1 influence line would be far enough away that it won't affect the adjacent building. That way, I don't have to deal with the liability of cracking the adjacent building, and the owner agreed. I didn't go so far as to use 1:1.5 or 1:2 influence line, so I figured it's a compromise between cost and liability, which is the basis of business to me.

@oldestguy It's not my place to evaluate others since I'm a new engineer myself. I appreciate you looking out for me though. I don't want to end up in the loony bin.

 

[r13]

Somebody suggested pre-project surveying, right? And monitor the movement of adjacent building throughout the construction. Good luck.