China
Africa
Explore chapters and articles related to this topic
General report 1: Geotechnical and environmental aspects
Published in Frans B.J. Barends, Application of Stress-Wave Theory to Piles, 2022
P. Hölscher, M.T.J.H. Smits, W. Van Impe
Using a well-known empirical model for the source and the transmission through the soil, they quantify the uncertainties in the model parameters and eventually the uncertainty in the predicted vibration level for a certain test site. It is shown that a simple model based on the cone penetration resistance yields approximate results. However because the uncertainty in the prediction is quantified, values can be given with a probability of exceedance. The uncertainties in the model can be reduced by site measurements. Reduction of the uncertainties gives lower predicted levels at the same probability of exceedance. More parameter studies at other sites and with other pile/hammer combinations would greatly contribute to the development of a simple model with a known reliability.
Policy implications of uncertainty integration in design
Published in Zhao-Yin Wang, Shi-Xiong Hu, Stochastic Hydraulics 2000, 2020
J.K. Vrijling, P.H.A.J.M. Van Gelder
The reliability-based decision-making procedure which has been applied in this paper can succesfully be used in the analysis of the optimal failure probabilities for the dikes along the Lake IJssel. The influence of the uncertainties lead to an increase in the probability of exceedance lines. When the hydraulic boundary conditions are modelled in an exponential way, analytical considerations can be given for the optimal probabilities of failure and the optimal dike heights.
Identification of elements exposed to flood hazard in a section of Trotus River, Romania
Published in Geomatics, Natural Hazards and Risk, 2018
Roxana Ţîncu, José Luis Zêzere, Gabriel Lazar
The probability of exceedance is directly related to the probability of an event of a certain magnitude to be exceeded. The probability of non-exceedance is obtained using Equation (2), where p′ correspond to the probability of non-exceedance and T is time in years (Dias et al. 2014; Bründl and Margreth 2015).
A new method for determining the design values of wave-induced hull girder loads acting on ships
Published in Ships and Offshore Structures, 2019
Jeom Kee Paik, Dong Hun Lee, Sang Jin Kim, Giles Thomas, Ming Ma
The summary of the wave probability calculations is provided in Table 6. Figure 14 shows the exceedance curve of the maximum wave-induced vertical bending moment for the example VLCC class tanker. The relationship between the probability of exceedance versus any physical parameter is very useful to determine nominal values of safety design and engineering for structural systems, where the physical parameters have been characterised in advance as actions or action effects by refined computations or testing for each of individual scenarios selected. Once the wave probability and the wave-induced loads are calculated for individual scenarios, the exceedance curve can be established by the following four steps. Step 1: Establish a table listing the frequency (probability) and target physical parameter for all of the scenarios considered, that can be made by combining Tables 4 and 6.Step 2: Based on the table established in Step 1, rearrange the order of scenarios in such a way that the scenario with the lowest maximum value of the parameter comes first and that with the highest maximum value comes last. Then, calculate the cumulative frequency (probability) in the table, as provided in Table 7.Step 3: Based on the table established in Step 2, calculate the exceedance frequency (probability) associated with the maximum value of the parameter. This is equal to the total frequency (probability) minus the cumulative frequency (probability) at the corresponding maximum value of the parameter, as provided in Table 8.Step 4: Determine the design loads or nominal value of structural designs in terms of the maximum parameter at an acceptable level of exceedance probability from the exceedance curve.