triaxial test triaxial test mmaha (Geotechnical) (OP) 30 Nov 16 21:17 please, can any one told me what is the difference between single stage and three stage triaxial test. Memo thanks. RE: triaxial test GeoPaveTraffic (Geotechnical) 1 Dec 16 12:36 In a three stage test, the same sample is tested at three different confining pressures. The first two stages are ran to a strain that approaches but does not cause failure. The third stage is strained to failure. A single stage test is run at a single confining pressure to failure. Mike Lambert RE: triaxial test mmaha (Geotechnical) (OP) 2 Dec 16 09:23 THANK YOU VERY MUCH MIKE. RE: triaxial test morecoffeeplz (Civil/Environmental) 17 Jan 17 20:47 The three stage test in most cases results erroneously high phi values as the two lower stresses are rarely taken out far enough for fear of failing the specimen.