Hello, I am writting to ask how to get the elastic modulus or undrained strength of the soil in the simulation model by using hypoplastic model in clay? Is there any formula that can be calculated from the hypoplastic model parameters, or is there some other way?Thank you so much.
A question about the hypoplastic model in clay
Related Articles

Velacs Project Data
WaiChing SunConstitutive Modelling1 Views 1,211
Dear colleagues, I want to ask your help — does anyone know where we can find all the test data from the old Velacs Project? If so, that would be […] 
MatLab m.file
Ala AljoranyConstitutive Modelling6 Views 2,180
Hi everyone, I’m trying to simulate a triaxial test by using Matlab, adopting the sand hypoplasticity model with strain softening but so far couldn’t succeed. Would anyone help me with […] 
Compile triax calibration software under windows
Hans Henning StutzConstitutive Modelling1 Views 1,400
1. Download install exe (32 or 64 bit) from https://cygwin.com/install.html 2. Choose a mirror site / click Next and select all packages you need for compiling: Type: “gcc” into search […] 
Hypoplastic Intergranular vs Triaxial Data
Hashmi SohawonConstitutive Modelling2 Views 1,215
Hi David, I am trying to reproduce some Triaxial data from Coop et al. (1995) using the Hypoplastic Model with Intergranular Strain Concept on Triax. So far, I cannot get […] 
Problems with the UMAT subroutine check_parms_DM of the SANISAND constitutive model
meng xiaoweiConstitutive Modelling3 Views 1,394
Where can I find the source of the content in the picture below in the UMAT subroutine check_parms_DM of the SANISAND constitutive model? 
consistent tangent stiffness calculation in hypoplasticity sand UMAT
Ran TuConstitutive Modelling1 Views 1,633
Dear all, Thanks for hypoplasticity sand UMAT provided by Prof. Masin. During studying hypo sand UMAT, I am encountered with a question about consistent tangent stiffness calculation. subroutine ”perturbate_h“ seems […] 
Cyclic/monotonic direct shear test (matlab driver)
anis kheffacheConstitutive Modelling2 Views 2,502
Hi everyone, i am trying to simulate DSS/cDSS test in drained/undrained conditions and I was wondering how the constraints matrices should be ? while it is easy to understand how […] 
SANISAND 2008 Model
MOHD SAQIBConstitutive Modelling0 Views 1,060
Hello Everyone, Can anyone have umat available for SANISAND 08 (Simple anisotropic sand plasticity model)?. Paper authored by Taiebat and Dafalias. They have used a closed type yield surface. Regards […]
Search SoilModels Website
Recent posts
 Few more Question on calculating lateral displacement of pile using hypoplastic clay model 3.10.2022
 A question about the hypoplastic model in clay 22.9.2022
 A HighCycle Accumulation Model for Sand (Niemunis et al., 2005) 6.9.2022
 Malaysian kaolin – Cyclic tests by Charles University 5.9.2022
 Problem in calculating Lateral displacement of the pile using Hypoplastic clay model 2.9.2022
 GTS NX 25.7.2022
 Special issue of Computers and Structures “Numerical simulation of multi‐physics phenomena in geotechnical structures” 25.7.2022
 Postdoctorate position at Nantes University (France) in geotechnical analysis of mutualized anchors 6.7.2022
 SIFEL – THM Model for Bentonite Barriers 27.6.2022
 ABAQUS job doesn’t make any increment 22.6.2022
 NorSand model for cyclic triaxial testing 9.6.2022
 Postdoc position at Charles University in the field of THM analysis of unsaturated and heated soil cyclic loading 30.5.2022
Recent Comments
 Wenbo Gu on A question about the hypoplastic model in clay
 David Mašín on A question about the hypoplastic model in clay
 Katarzyna DołżykSzypcio on Download package of a complete dataset “Karlsruhe fine sand – Cyclic tests (T. Wichtmann)”
 Wenbo Gu on A question about the hypoplastic model in clay
 Muhammad Ahmad on A question about the hypoplastic model in clay
 Wenbo Gu on A question about the hypoplastic model in clay
 Muhammad Ahmad on A question about the hypoplastic model in clay
 Muhammad Ahmad on Problem in calculating Lateral displacement of the pile using Hypoplastic clay model
 David Mašín on Problem in calculating Lateral displacement of the pile using Hypoplastic clay model
 Jie Wang on Interpreting results of sand hypoplastic model with Abaqus VUMAT
 Muhammad Ahmad on Problem in calculating Lateral displacement of the pile using Hypoplastic clay model
 David Mašín on Problem in calculating Lateral displacement of the pile using Hypoplastic clay model
 Raj Banerjee on SANISAND Abaqus UMAT and Plaxis implementations
 Amrane Moussa on Special issue of Computers and Structures “Numerical simulation of multi‐physics phenomena in geotechnical structures”
 Riccardo Zabatta on Modelling TX monotonic compressive test with ABAQUS and SANISAND – not working
 Haibo Jiang on Download Package for Hypoplastic interface model and UMAT – FRIC interface
 Giada Orlando on Hardening Soil Model in Abaqus
 Sanchari Mondal on Modelling TX monotonic compressive test with ABAQUS and SANISAND – not working
Undrained shear strength is calculated using Hypoplastic model by the combination of state dependent variables SDV7, SDV9, SDV15 i.e. Void ration , Effective stress and OCR using equation…using equation
Su=o.18(σ’v)OCR^0.9….. Further the relation between these state dependent variables can be found in the the chapter 6 of the book of Dr. David masin”Modelling of of soil behavior with hypoplastcity’
e=expN−λ∗ln(OCR∗p) −1
Good luck and thank you
Hello Dr. Muhammad Ahmad
Thank you so much for your answer. It is really helpful for me. Could you please tell me where I can find the full meaning of the state dependent variables from SDV1 to SVD 16? I am very appreciate for your help.
Here is the link… Thank you
http://web.natur.cuni.cz/uhigug/masin/plaxumat/node6.html
Many thanks to you !
Hi Muhammad, thanks for replying. And Wenbo: For clarification, the formula for undrained shear strengh (Eq. 6.22 from the book Masin, 2019) is cu=p*M*OCR/4, where M=6*sin phic/(3sin phic) and OCR=pe/p with pe=exp((Nln(1+e))/lambda). Elastic modulus is only defined for small strain stiffness version of the model (the one with intergranular strain), where the shear modulus G0=Ag(p/pr)^ng with pr=1 kPa.
Thank you for your clarification Prof. Mašín !