..tutorialcpt

Tutorial determine state parameters using GEOLIB+

With the GEOLIB+ package it is possible to determine state parameters (OCR, POP and yield stress) of the soil, as described in [11]. All the methods are implemented as static methods in the StateUtils.

Calculate yield stress, OverConsolidation Ratio and Pre Overburden Ratio

With the function calculate_yield_stress_prob_parameters_from_cpt() the mean and standard deviation of the yield stress can be determined. The input for this function is the effective stress and the q_net at the depth of interest. Furthermore the function requires the mean S and mean m, which can be determined as described in Tutorial determine Shansep parameters using GEOLIB+. Lastly, the function requires the mean Nkt and the variation coefficient of q_net/ Nkt of the corresponding soil, which can be retrieved following Tutorial determine Nkt values using GEOLIB+. Below an example is given on how to calculate the probabilistic parameters of the yield stress.

from geolib_plus.shm.nkt_utils import NktUtils

effective_stress = 15.8
q_net = 180
mu_S = 0.38
mu_m = 0.8
mean_nkt = 16.01
vc_qnet_nkt = 0.169

mean_yield_stress, std_yield_stress = StateUtils.calculate_yield_stress_prob_parameters_from_cpt(effective_stress, q_net,
                                                                                                 mu_S, mu_m,
                                                                                                 mean_nkt, vc_qnet_nkt)

Calculating the probabilistic parameters of the POP and the OCR works in a similar wat, compared to calculating the yield stress. In order to calculate the POP parameters, the function calculate_pop_prob_parameters_from_cpt() can be used. In order to calculate the OCR parameters, the function: calculate_ocr_prob_parameters_from_cpt().

It is also possible to calculate the characteristic values of the yield stress, POP and OCR. This can be done by using the following corresponding functions: calculate_characteristic_yield_stress(), calculate_characteristic_pop() and calculate_characteristic_ocr()