I design cast in place piles using the IBC and always use a partial length cage and full length center bar, except in high seismic zones where liquefaction may occur at the interface of soft/hard zones (in which case I may extend a four bar deeper). Per the IBC you only need the full cage to the...
This is a general question about the purpose of the IBC code. Is it just a guide or do we have to design to it with no exceptions? Or is it intended to be a guide for the local for the building official in establishing the local code?
We have performed pile load tests and based on the IBC...
The steel supplier sent us the wrong bars so we are going to use the ZAP screw lock system to splice short thread bars to the non-thread bars. The ZAP Type 2 splices are suitable for GR75 bars. The std plate & nut will then be added to the spliced thread bars. I will leave 4" clearance at the...
I am designing single bar tension reinforcement for piles - the tension center bar is GR75, non-threaded. I was planning on using terminators to develop the bar but they are limited to GR60 bars. If the bars were threaded I would use a plate and nut system; the bars are already on site so I...
The flange of 229 was damaged - I saw it. The GC twisted the section before it was placed in the drilled hole. This view is from behind the wall-you can see that 229 is twisted.http://files.engineering.com/getfile.aspx?folder=d37a05d0-02b4-41c8-b770-2546af51bb00&file=CIMG1333.JPG
One thing you will notice if you look closely is that pile 229 is twisted clockwise in plan view from the wall top. The pile was installed that way, with a bend in the flange, as it was damaged during construction. The bend was at the roadway grade elevation. This surely reduced the bending...
Doc09
The spacing between the piles is 5'. With typical pile depth of 20' bgs (36' total, 7' rock embedment), 16.5 deg slope, full water pressure behind wall, no contribution to stiffness from concrete (it is cracked), the deflection at the top using a p-y analysis is 21". The original design...
Thanks for all the responses. Here is a pic of the wall.http://files.engineering.com/getfile.aspx?folder=7ab9463b-43c6-47e1-9d69-85e2dbf84910&file=CIMG1294.JPG
Geopave/PEInc: the wall was designed like a backyard retaining wall w/ no slope; the design assumed that active conditions would develop behind the wall. This does not appear correct, but they say the wall design is suitable. However, there are portions of the wall on the same slope where it is...
My firm (acting as a subcontractor) has installed a soldier pile lagging wall that has failed by excessive deflection (2 ft in some cases). The wall is 15 ft high, with precast lagging panels and HP14x89 beams in 24" concrete filled holes. The purpose of the wall is to retain a landslide in a...
You are correct - based on IBC 2006, cap fixity is not required unless you have a SDC=C or worse. However, if the pile cap & pile head do not rotate, fixity will be implied and the maximum moment will occur at the pile top. I never understood how you can design for free head conditions if the...
I design pile reinforcement everyday- determine moment and shear distribution and design like a beam-column. I use CSIcol or PCAcol w/ factored loads to determine the amount of reinforcement. Newer codes address the minimum cage length and shear reinforcement, and the need for fixity at the pile...
All good points above. Small pile caps are assumed to be rigid so all the load goes into the piles. If the piles deflect there may be some load sharing between the piles and cap, and in reality this would reduce the load on the piles (and increase the pile FS). This is the basic idea of a pile...
The reason I reduce Kp by a FS(~1.5) is since the wall tip will not fully mobilize Kp unless you are in a failure condition. Obviously for a proper design the wall tip does not move to this extent. Thus a reduced mobilized Kp should be used for design as it takes much more movement to mobilize...
DRC1- some education is prudent here.
We design & install continuous flight auger (CFA) & DeWaal piles (DWP), as well as drive precast piles, micro-piles, etc. Under the right conditions, driven piles are the proper choice - we have driven thousands of them.
CFA piles have been used for design...