Hmmm. 4ft is pretty tight pile spacing and should give the soil lots of opportunity to arch (unless the contractor does something silly like open all of the bays and chip away all of the soil behind the pipes all at once). But keep in mind, if your intent is to lag behind pipe piles, you will...
In my experience, it is best to avoid lagging within the influence of adjacent buildings and construct a tanget or secant wall as you previously suggested to your client (however, based on your sketch, it doesn't look like you have clearance for a tangent or secant wall). This is not for...
In my area, the sequence is to drill the soldier piles, drill the dewatering wells, draw down the water, then excavate.
I suppose in some areas, it may be preferable to draw down the water and then drill the soldier piles, but where I am the contractors are content to drill in wet ground with...
Here are some things to consider:
1. Has a specialty contractor already been selected to construct this support of excavation system? If so, ask them what detail they like.
2. What are you using for the struts? W/HP shapes? Pipes? This will influence the detail.
3. Consider...
For Stage 1, I would expose the entire pile web (without disturbing the soil/fill behind the outside of the back flange) and install the lagging against the inside face of the back flange. A piece of steel angle could then be welded to the web of the pile to sandwich the lagging in place. The...
I'm not suggesting that you yield any of the anchors. Basically, you apply a tensile load to the anchor with a hydraulic jack until the nut is just barely lifted off the bearing plate/pile/wall/whatever it's bearing against. This point can usually be surmised by an abrupt reduction in gain of...
I imagine your contractor would be reluctant to re-stress all the anchors using a hydraulic jack, but perhaps you could do a do a lift-off test of a single anchor. Basically, mount the jack on the anchor and extend the ram until the hydraulic pressure abruptly increases. This pressure can then...
I personally haven't pre-tensioned an anchor using torque (I've only ever used a hydraulic jack), but the Williams Form website says the following about torque: "The second method of prestressing is to use a torque tension method. Unlike competing products, Williams full, concentric, rolled...
FHWA has some good publications online discussing drilled shaft inspection. I would have a read through those. You could also consult the website of companies like Pile Dynamics.
For a wall such as this, I would recommend you check it by hand. Software can sometimes obscure how stable your wall is. To check the stability of the wall, determine the embedment depth at which the sum of moments due to active and passive earth pressures (and surcharge if present) about the...
It is correct to continue the active pressure on the retained soil side of the sheet pile. You say "Thinking about this problem logically, burying a steel sheet pile wall underground with soil on each side should not generate any force on the sheet pile wall." This is incorrect. Lateral earth...
gte447f - you are correct about the degradation of the coir logs. I should have educated myself more about their lifespan before I responded. I initially suggested them because I was thinking of something that could act as a filter to prevent loss of your wall base material (something that...
I take it that this is in a private owner's backyard and thus aesthetics are important and loss of usable space would be preferably avoided. I wonder if you could do something with coir fibre logs in front of the wall to build up the grade a little. If you wanted to assure yourself that these...
I imagine you are using Rankine earth pressure to check the stability of this wall. Rankine substantially underestimates passive pressure. Instead, try using log-spiral theory for the passive pressure at the embedded portion of the wall. This may not solve your problem entirely but you'll...
Another option to consider is some type of buried arch structure. I'm not sure where you are located but if you're in the US or Canada, reach out to underground product suppliers like DSI, Jennmar, or Reinforced Earth. Their products are typically not used on habitable structures (unless...
This is a bad idea. Please contact a structural engineer with experience in underground structures. I do not want to be disrespectful, but I also don't want you to attempt this project as you've described it.
If (and this is a big if) you can satisfy your self that the rock will not apply lateral load, here are a few text sources for reduced lateral pressure from smaller active soil wedges. If you can't get ahold of hardcopies, try Internet Archive.
Chapter on Fascia Walls in Geotechnical...
Though I have not quantified the rotational stiffness of the connection between the wide flange and the pipe with any sophisticated analysis, I can content myself that the connection can be approximated as a rigid joint. The web of the wide flange is slotted quite deep into the pipe (750mm is...
Thank you both for your replies! They are very helpful. I've found the paper by Dalal which Lomarandil referenced. It looks very promising. I've also provided a link to the pdf below for anyone visiting this thread in the...
