FOUNDATION FOR DRILLING RIG
FOUNDATION FOR DRILLING RIG
(OP)
i was assigned with a project to design a precast foundation for a drilling rig.
the tower of the rig, the hook load is supported by a truss substructure which lies on concrete foundation.
because i need to design it precast, i am constraint by dimensions (not to exceed the foundation weight of 25t for transportation reason).
Has anybody designed this kind of foundation? the whole structure is supported by 4 beams. i am thinking to divide the foundation in 2 or three pieces.
however, i'm not sure about the settlements in this case. Any comments , thoughts?
the tower of the rig, the hook load is supported by a truss substructure which lies on concrete foundation.
because i need to design it precast, i am constraint by dimensions (not to exceed the foundation weight of 25t for transportation reason).
Has anybody designed this kind of foundation? the whole structure is supported by 4 beams. i am thinking to divide the foundation in 2 or three pieces.
however, i'm not sure about the settlements in this case. Any comments , thoughts?





RE: FOUNDATION FOR DRILLING RIG
RE: FOUNDATION FOR DRILLING RIG
RE: FOUNDATION FOR DRILLING RIG
RE: FOUNDATION FOR DRILLING RIG
RE: FOUNDATION FOR DRILLING RIG
Your sketch looks like the churn drills we used to use in New York. These have significant dynamic loads. Or is it a rotary rig?
A geotech should provide you with foundation soils requirements. You will likely have a varying load which may require reduce soil bearing.
I really like Ron's idea of dragline mats.
Bob
RE: FOUNDATION FOR DRILLING RIG
as these foundations will be used in different sites, i need to assign maximum allowable stress on soil, so that the geotechnical engineer should verify if soil of a specific site can support those stresses.
i attached of my idea, which looks like what Ron suggested.
anybody has any contraindications /comments/ suggestions?
RE: FOUNDATION FOR DRILLING RIG
You really have to put some dimensions and details on you sketches, and you have to show where the loads are actually applied, so we can see what you are dealing with. I assume the four sets of beams B/1 & B/2 are part of the drilling rig. But, that the loads are actually applied at a few discrete points on those beams. You are basically right about the need for some GeoTech involvement, and to develop your design for some basic (allowable) soil pressure. But, I think you should turn your thinking around a little. Talk with some local GeoTech guys, right now and learn something about the soil conditions in a given drilling region, and use their info. as the basis for your allowable design soil loads. Then have a local precasting company make the planks for you with some sort of lifting features on them. You will still want the GeoTech guy to look at each drilling site to confirm the soil conditions before you put down your foundation pad.
RE: FOUNDATION FOR DRILLING RIG
I did a job where we carefully designed a bearing pad installation for some very poor soils. The contractor brought in a crane to place the pads, but he set up in the poor soil and almost toppled the erection crane.