Evaluation of liquefaction induced lateral displacements using genetic programming
Introduction
During an earthquake, significant damage can result due to the ground movement and instability of the soil in the area affected by internal seismic waves. One of the common phenomena resulting from earthquake is liquefaction in loose saturated sands. Liquefaction is known as one of the major causes of ground movement and failure related to earthquake. It is believed to occur when the pore pressure approaches the confining pressure under earthquake loading where, as a result of a rapid and dramatic loss of soil strength, it can initiate movement of large blocks of soil with amplitudes ranging from a few centimeters to 10 m or more, eventually causing extensive damage to buried utilities, lifeline networks and many other underground and surface civil engineering structures.
Liquefaction induced lateral displacement generally occurs on gentle slopes ranging from 0.3° to 3° [1] founded on loose sand with groundwater level fairly close to the ground surface; however, open faces like stream channels are also susceptible to lateral spreading.
Liquefaction occurrence and the resulting lateral spreading depend on the physical and mechanical characteristics of the soil layers in the site, the depth of the water table, the intensity and duration of the ground shaking, the distance from the source of the earthquake and the seismic attenuation properties of in situ soil. Because of the participation of a large number of factors, the determination of liquefaction-induced lateral displacement is a complex geotechnical engineering problem. Several researchers have attempted to model this phenomenon using different techniques, a summary of which is presented in the following section.
Section snippets
Current practice in estimation of liquefaction induced lateral displacement
Due to the complexity of the problem, several analytical, numerical and empirical methods have been developed to estimate liquefaction induced lateral spreading.
Genetic programming
Genetic programming (GP) is an evolutionary computing method that generates a structured representation of the data provided. It imitates the biological evolution of living organisms. The technique which was introduced in the early 90s by Koza [23] makes use of the principles of genetic algorithms (GAs) to manipulate and optimize a population of computer models composed of functions and terminals in order to find a model that best fits the problem. These functions and terminals represent the
Genetic programming approach for estimation of lateral spreading
In this paper a new approach is presented for the assessment of liquefaction induced lateral displacement using genetic programming. A database of SPT-based case histories, compiled by Youd and Bartlett [19] has been used in this study to find the relationship between liquefaction induced lateral displacement and its contributing factors. This database is a revised version of the original database which was used previously by Bartlett and Youd [17], [18]. The corrections and modifications which
GP model of lateral displacement for free face cases
In the GP procedure, initially a number of potential models are randomly generated. Each model is trained and tested using the training and testing cases respectively. The fitness of each model is evaluated by minimizing the error i.e., the difference between the predicted and measured lateral displacements. If the errors calculated for the models in the population do not meet the termination criteria the evolutionary process continues in order to create a new generation of models. The
GP model of lateral displacement for cases involving gently sloping ground
The database also includes 256 case histories of lateral displacement in gently sloping ground. These cases were used for the development of the second GP model for sloping ground conditions. Of these, 201 cases (78.5%) were used for training of the GP model and the remaining 55 cases (21.5%) were used for validation. After the analysis of a number of different alternative models, the following model was found to be the most appropriate model for gently sloping ground condition:
GP models for moderate lateral displacements
It is seen from Fig. 5, Fig. 6 that, in general, the GP models (Eqs. (5), (6)), predict lateral displacements with high accuracy, particularly for cases with displacements greater than 1.5 m. However, as shown in Figs. 7(a) and (b) (which are the enlarged views of the initial parts of Figs. 5(a) and (b) respectively), this approach does not provide the same level of accuracy in the estimation of lateral displacements for cases with moderate displacements of less than about 1.5 m. Youd et al. [19]
Sensitivity analysis
In order to examine the sensitivity of the models to data set size, the data sets for free face and gently sloping ground conditions were gradually reduced in size to 160, 120, 80 and 60 cases. For each case, the reduced data set was divided into training and validation subsets and GP models were constructed and validated. Table 6 shows the results of the sensitivity analysis for the GP models constructed with different number of cases. It is shown that the proposed GP methodology performs well
Results and discussion
A new approach, based on genetic programming, has been presented for prediction of liquefaction-induced lateral displacements during earthquake. Two separate models have been presented, one for whole range of displacements and one for moderate displacements of up to 1.5 m. Fig. 5, Fig. 6, Fig. 8, Fig. 9 show the prediction capabilities of the GP models as plots of measured versus predicted displacements. It is shown that the models are capable of learning, with a very high accuracy, the complex
Summary and conclusion
Determination of liquefaction induced lateral displacements during earthquake is a complex geotechnical engineering problem due to the heterogeneous nature of soils and the participation of a large number of factors involved.
In this paper, a new approach was presented, based on genetic programming, for determination of liquefaction induced lateral displacements due to earthquake. Two general GP models were trained and validated using a database of SPT-based case histories for free face and
Acknowledgements
This work used software developed by Ozario Giustlisi (Technical University of Bari) and Dragan Savic (University of Exeter).
References (25)
- et al.
Study on permanent ground displacements induced by seismic liquefaction
Comput Geotech
(1987) - et al.
The mechanism and simplified procedure for analysis of permanent ground displacement due to liquefaction
Soil Foundat
(1992) - et al.
Prediction of permanent displacement of liquefied ground by means of energy principle
Soils Foundat
(1992) - et al.
A neural network model for liquefaction induced horizontal ground displacement
J Soil Dyn Earthquake Eng
(1999) - et al.
Evaluation of lateral spreading using artificial neural networks
J Soil Dyn Earthquake Eng
(2005) - et al.
Genetic programming: principles and applications
Eng Appl Artificial Intell
(2001) - Committee on Earthquake Engineering. Liquefaction of soils during earthquakes, Committee on Engineering and Technical...
- Rauch AF. EPOLLS: An empirical method for predicting surface displacements due to liquefaction-induced lateral...
- et al.
Progressive failure of Lower San Fernando Dam
J Geotech Eng
(1993) - et al.
Postearthquake deformation analysis of Wildlife site
J Geotech Eng
(1994)
Cited by (138)
Predicting the small strain shear modulus of sands and sand-fines binary mixtures using machine learning algorithms
2024, Transportation GeotechnicsAssessment of liquefaction-induced lateral spread using soft computing approaches
2023, Gondwana ResearchSmart prediction of liquefaction-induced lateral spreading
2023, Journal of Rock Mechanics and Geotechnical EngineeringPrediction of lateral spreading displacement using conditional Generative Adversarial Network (cGAN)
2022, Soil Dynamics and Earthquake EngineeringUse of soft computing techniques for tunneling optimization of tunnel boring machines
2021, Underground Space (China)Citation Excerpt :Jain et al. (2004) showed that the ANN model captured some physical process features in a rainfall-runoff ANN model. Some scholars used soft computing methods to establish simplified formulas for solving geotechnical engineering problems (Javadi, Rezania, & Mousavi, 2006; Johari, Habibagahi, & Ghahramani, 2006; Padmini, Ilamparuthi, & Sudheer, 2008; Samui, 2008). Kim et al. (2001) used neural networks to predict ground surface settlements during the construction of the Seoul subway.