Trench In front of Cantilevered Wall
Trench In front of Cantilevered Wall
(OP)
I am designing a cantilevered soldier pile wall. There is a 7.5' deep utility trench 5' from the face of the wall. The elevation of rock is at the top of the trench. The rock is weathered limestone with an RQD of 75. The retained soil is clay with a Qu of 1 tsf. The maximum height of the wall measured from the bottom of the trench is 25 ft. How would you go about modeling this?
Here is what I have done. I am using Cwalsht for the design. I assume the passive wedge acts over 3 shaft diameters. I have the soldier piles spaced at 6'-0" and am using 2' diameter shafts. To model the rock I assumed a clay with a cohesion of 4000. My problem is when I model a near vertical face in cwalsht for the rock it is giving me unconservative results (7' of penetration, an elevation near the bottom of the trench). I am having a hard time trying to come up with the contribution of the rock between the drilled shaft and the trench. Does anyone have experience with this?
Here is what I have done. I am using Cwalsht for the design. I assume the passive wedge acts over 3 shaft diameters. I have the soldier piles spaced at 6'-0" and am using 2' diameter shafts. To model the rock I assumed a clay with a cohesion of 4000. My problem is when I model a near vertical face in cwalsht for the rock it is giving me unconservative results (7' of penetration, an elevation near the bottom of the trench). I am having a hard time trying to come up with the contribution of the rock between the drilled shaft and the trench. Does anyone have experience with this?





RE: Trench In front of Cantilevered Wall
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RE: Trench In front of Cantilevered Wall
RE: Trench In front of Cantilevered Wall
www.PeirceEngineering.com
RE: Trench In front of Cantilevered Wall
RE: Trench In front of Cantilevered Wall
www.PeirceEngineering.com
RE: Trench In front of Cantilevered Wall
www.PeirceEngineering.com
RE: Trench In front of Cantilevered Wall
RE: Trench In front of Cantilevered Wall
www.PeirceEngineering.com
RE: Trench In front of Cantilevered Wall
RE: Trench In front of Cantilevered Wall
RE: Trench In front of Cantilevered Wall
www.PeirceEngineering.com
RE: Trench In front of Cantilevered Wall
RE: Trench In front of Cantilevered Wall
www.PeirceEngineering.com
RE: Trench In front of Cantilevered Wall
www.PeirceEngineering.com
RE: Trench In front of Cantilevered Wall
It would be useful to know what your utility is, I presume its long, segmental pipe (what stick length compared to your 6' soldier pile spacing?). You may want to specify using shorter pipe sections. I presume this is not something that can be directional drilled.
I agree with the previous concern that your contractor may not be able to dig a vertical trench in fractured rock, and may effective excavate all the way back to the soldier piles. An option might be to require the utility contractor to pre-excavate and cast concrete beams on the top either side of the trench (say 3' deep, in short segments), then use these for bracing against with heavy jacks at spacing as needed while digging to full depth. The jacks also could be rearranged to allow insertion of longer sticks.
RE: Trench In front of Cantilevered Wall
Find out from the utility company what pipe length and diameter they are using and check that this can be inserted between the concrete struts. If you need higher spacings than us a concrete transfer beam between the struts.
RE: Trench In front of Cantilevered Wall
Have you considered a double sheetpile wall?
RE: Trench In front of Cantilevered Wall