EireChch
Geotechnical
- Jul 25, 2012
- 1,343
Hi Everyone,
I am a graduate engineer with one years experience with my company. I am involved with a project now that involves the re-construction of a internal slab of a portal framed building. The portal columns are supported on isolated pads with the internal slab poured independently. The reason for the reconstruction of the slab is that the building is an earthquake damaged building in Christchurch, New Zealand. We are also investigating the potential to re-level column pads with screw piles but that is another days topic.
So to my question. In Christchurch here there is a method/guidance paper that is used to assess the bearing capacity for small structures. Its called the Stockwell Method. Attached is a copy of the paper. In summary, its based off Scala Penetrometer blows per 150mm which is plotted on a graph that gives an allowable bearing capacity. We are proposing to undertake 4 hand auger tests with scala penetrometer testing throughout and extending to 2m beyond the base of the borehole. Usually in ChCh the HAs collapse at around 2m due to the high GW and loose sand material.
My question is, would it be appropriate to use this Stockwell method to assess the bearing capacity for the design of a new slab? I was thinking that this would be acceptable as the loads will be relatively light. The building is a plastics factory, approx 500 sq meters.
If you guys think this method is appropriate i have some questions on the method itself but will see what the initial response is.
I also have a CPT on a neighbouring site, approximately 50m away, that I will assess the bearing capacity using Robertsons method for comparison. If anyone is interested, I will attach my calcs for people to have a look. In work we have correlations for converting scala blows to phi etc so I will also check the bearing using the Terzaghi or Meryhoff methods. My usual work was just report writing for the rebuild of earthquake damage houses. Usually the bearing capacity is based on the guidance document in Christchurch i.e. 2 blows per 100mm = 200kPa and 5 blows per 100mm = 300kPa so assessing bearing capacity using these types of methods is a little new to me so please pardon my lack of knowledge. Also please pardon my metric units, its all i know!!!
At the end of the day all my work will be reviewed by my senior engineer so i will ask for his advice throughout the project also but i just said id ask here for another perspective.
Any advice is much appreciated.
Regards
I am a graduate engineer with one years experience with my company. I am involved with a project now that involves the re-construction of a internal slab of a portal framed building. The portal columns are supported on isolated pads with the internal slab poured independently. The reason for the reconstruction of the slab is that the building is an earthquake damaged building in Christchurch, New Zealand. We are also investigating the potential to re-level column pads with screw piles but that is another days topic.
So to my question. In Christchurch here there is a method/guidance paper that is used to assess the bearing capacity for small structures. Its called the Stockwell Method. Attached is a copy of the paper. In summary, its based off Scala Penetrometer blows per 150mm which is plotted on a graph that gives an allowable bearing capacity. We are proposing to undertake 4 hand auger tests with scala penetrometer testing throughout and extending to 2m beyond the base of the borehole. Usually in ChCh the HAs collapse at around 2m due to the high GW and loose sand material.
My question is, would it be appropriate to use this Stockwell method to assess the bearing capacity for the design of a new slab? I was thinking that this would be acceptable as the loads will be relatively light. The building is a plastics factory, approx 500 sq meters.
If you guys think this method is appropriate i have some questions on the method itself but will see what the initial response is.
I also have a CPT on a neighbouring site, approximately 50m away, that I will assess the bearing capacity using Robertsons method for comparison. If anyone is interested, I will attach my calcs for people to have a look. In work we have correlations for converting scala blows to phi etc so I will also check the bearing using the Terzaghi or Meryhoff methods. My usual work was just report writing for the rebuild of earthquake damage houses. Usually the bearing capacity is based on the guidance document in Christchurch i.e. 2 blows per 100mm = 200kPa and 5 blows per 100mm = 300kPa so assessing bearing capacity using these types of methods is a little new to me so please pardon my lack of knowledge. Also please pardon my metric units, its all i know!!!
At the end of the day all my work will be reviewed by my senior engineer so i will ask for his advice throughout the project also but i just said id ask here for another perspective.
Any advice is much appreciated.
Regards