uniaxial compressive strength is common test in rock mechanics. this test is very important and so far many relationships are provided to predict it.
I want to know application of this parameter in different modeling. Such as oil reservoir modeling, hydraulic fracturing modeling or in modeling software such as petrel.
Your question is not very clear, the uniaxial compressive strength is used in the design of foundation on rock. I suggest you to read the text book titled Rock Mechanics by Ramamurthy.
Uniaxial compressive strength is used to design many geotechnical engineering structures such as foundations and thus, it is a very valuable parameter. Many models were available in the literature based on Uniaxial compressive strength (it is also referred to as unconfined compressive strength, UCS). UCS is correlated with Brazilian tensile strength test, point load index test, Schmidt hammer, ultrasonic velocity tests, etc. You can refer to the paper:
"PREDICTION OF UNCONFINED COMPRESSIVE STRENGTH OF ROCKS: A REVIEW PAPER" for many predictive models using UCS in different applications.
UCS value can give a proper and exact idea about the rocks compressive strength. Before construction, we need to investigate the site properly. Despite of some in-situ tests, we need to comply some ex-situ (laboratory) tests also. UCS is among the ex-situ tests.
During UCS, the specimen is subjected to compressive stress from one direction and measure the maximum stress rate that it would sustain over time. This limit is helpful to detect the weak side and the ultimate limit of deformation too. Unfortunately, this parameter has less applications on your required software's; but you can use it on Rockware, GeoCAD and AutoCAD also, to delineate the geo-technical qualities of underlying rocks.
I think my explanation will reach your query. For more details, see book -"Soil mechanics and foundation" by B.C Punmia.
Thank you.
UCS qualifies strength of rock materials. Scale effects can modify the values of this parameter, whose relevance in modelling is depending on the numerical approach and discretization (FEM, DEM, Ubiquitous joints, Particle modelling, etc). Other geological factors influence the proper choice of the value, such as anisotropy, confinement of real structures etc. So I suggest to go back to some textbooks in rock mechanics characterization and try to collect as many as possible real data concerning your case history; correlations are useful, but direct experimental knowledge can be better. Regards
UCS/Uniaxial test is quick and easy test to determine the shear strength of saturated cohessive soils.
UCS is an important parameter to determine rock mass index like RMR and Q System. Indirectly UCS is helpful to select the support in tunneling as well as in
underground Mining.
It is useful for some potential applications related to geomechanics which are wellbore stabiliy analysis, hydraulic fracturing (stimulation), sand production, and prediction of rock drillability.
Your query is directly related to oil and gas rather than ordinary civil engineering projects as many assumed above. I confess my relative ignorance on hydrocarbon reservior issues. However I wonder if UCS is applicable for reservoir engineering. My impression is that UCS cannot simulate three dimensional stresses on a rock element in such reservoirs (most of them at least 2 to 3 km below ground). My guess would go for triaxial testing so that sigma 2 and sigma 3 lateral (confining) stresses can be simutlated in the lab. Uniaxial (where sigma 2 = sigma 3 = 0) could be of some assistance in well design only.
Many relevant answers already given by others. I could add - with empirical developments bias: UCS (as already partially suggested) is a direct part of the RMR rating, but it is a 'when needed' part of Q-value determination, via SRF, if the local principal stress/UCS ratio is more than approx. 0.4. (But recently this has been shown (B.Shen and Barton, 2016) to be due to sigma t / Poisson's ratio: i.e. extensional strain failure in tension (even if all three principal stresses are compressional). At higher stress levels, fracture propagation will be by shear. So although we (actually incorrectly) use UCS to trigger an expectation of fracture initiation (and AE in a lab-test), the tensile strength is mobilized first (with help from Poisson's ratio), then shear strength, and the highest strength component UCS (or its confined equivalent) is seldom if ever actually mobilized. Exactly the same applies to cliff heights in weak materials and mountain wall heights in strong materials. The two weaker links are prioritized over UCS in geomorphology (terrain formation) and structural geology (the big scale).
UCS is however helpful for normalizing Q to Qc (= Q x UCS/100) for improved correlation to P-wave velocity and static deformation modulus (both are depth or stress dependent: 'Emass' modellers please note). UCS is also useful in Qtbm (TBM performance prognosis) for estimating SIGMA the approx. rock mass strength (approx. range 1 to 100 MPa) for comparing with mean cutter force. And finally in BB shear strength of joints JCS (when weathered) may approach the value of UCS if there is no weathering: in other words a fresh fracture surface during progressive (non MC, non HB) failure beneath say a major rock slope.
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