Search citation statements
Paper Sections
Citation Types
Year Published
Publication Types
Relationship
Authors
Journals
Many of the more common causes of physical failures or serious remedial problems of engineering works are related to the construction or operation and maintenance phases of a project and involve either controversies or errors of geologic judgment. Mistakes and misunderstandings that impact on a project, including an incorrect design, may be due to any of several causes, such as a misinterpretation of available geological facts, inadequate factual background data, or misunderstanding, misjudgment, or poor forecasting of the geolpgic changes that occur with time and/or operation. Frequently the errors of judgment committed are related to the cost/benefit and/or calculated-risk evaluations of a project, as discussed later in this chapter. Many faulty interpretations of areal and site-specific geologic conditions have been traced to a lack of input by mature, field-experienced geologists. Even more frequently the errors are a function of insufficient funds for adequate investigations. Management is often under pressure to expedite the investigative stage of the project; in a few instances, site assessment has been attempted by inexperienced individuals or non-geologists, as in the case of the St. Francis dam failure (Chapter 22, this volume). On rare occasions, accusations have claimed incompetence or intentional misinterpretation of the geologic environs for self-serving purposes. However, the authors are unaware of any such instance of fraudulent practice by a professional geologist. Judgment plays a particularly important role in the planning stage of most major engineering works; for example, in comparing alternative sites for structures or determining routes for aqueducts or highways. Errors of judgment during planning may lead to design problems or result in a failure to achieve the maximum potential benefits from the project.
Many of the more common causes of physical failures or serious remedial problems of engineering works are related to the construction or operation and maintenance phases of a project and involve either controversies or errors of geologic judgment. Mistakes and misunderstandings that impact on a project, including an incorrect design, may be due to any of several causes, such as a misinterpretation of available geological facts, inadequate factual background data, or misunderstanding, misjudgment, or poor forecasting of the geolpgic changes that occur with time and/or operation. Frequently the errors of judgment committed are related to the cost/benefit and/or calculated-risk evaluations of a project, as discussed later in this chapter. Many faulty interpretations of areal and site-specific geologic conditions have been traced to a lack of input by mature, field-experienced geologists. Even more frequently the errors are a function of insufficient funds for adequate investigations. Management is often under pressure to expedite the investigative stage of the project; in a few instances, site assessment has been attempted by inexperienced individuals or non-geologists, as in the case of the St. Francis dam failure (Chapter 22, this volume). On rare occasions, accusations have claimed incompetence or intentional misinterpretation of the geologic environs for self-serving purposes. However, the authors are unaware of any such instance of fraudulent practice by a professional geologist. Judgment plays a particularly important role in the planning stage of most major engineering works; for example, in comparing alternative sites for structures or determining routes for aqueducts or highways. Errors of judgment during planning may lead to design problems or result in a failure to achieve the maximum potential benefits from the project.
Soil liquefaction is a major concern for structures constructed with or on sandy soils. This paper describes the phenomena of soil liquefaction, reviews suitable definitions, and provides an update on methods to evaluate cyclic liquefaction using the cone penetration test (CPT). A method is described to estimate grain characteristics directly from the CPT and to incorporate this into one of the methods for evaluating resistance to cyclic loading. A worked example is also provided, illustrating how the continuous nature of the CPT can provide a good evaluation of cyclic liquefaction potential, on an overall profile basis. This paper forms part of the final submission by the authors to the proceedings of the 1996 National Center for Earthquake Engineering Research workshop on evaluation of liquefaction resistance of soils.Key words: cyclic liquefaction, sandy soils, cone penetration test
Fokker-Planck-Kolmogorov (FPK) equation approach has recently been developed to simulate elastic-plastic constitutive behaviors of materials with uncertain material properties. The FPK equation approach transforms the stochastic constitutive rate equation, which is a stochastic, nonlinear, ordinary differential equation (ODE) in the stress-pseudo time space into a second-order accurate, deterministic, linear FPK partial differential equation (PDE) in the probability density of stress-pseudo time space. This approach does not suffer from the drawbacks of the traditional approaches such as the Monte Carlo approach and the perturbation approach for solving nonlinear ODEs with random coefficients. In this study, the existing one dimensional FPK framework for probabilistic constitutive modeling of soils is extended to multi-dimension. However, the multivariate FPK PDEs cannot be solved using the traditional mathematical techniques such as finite difference techniques due to their high computational cost. Therefore, computationally efficient algorithms based on the Fourier spectral approach are developed for solving a class of FPK PDEs that arises in probabilistic elasto-plasticity. This class includes linear FPK PDEs in (stress) space and (pseudo) time-having space-independent but time-dependent, and both space-and time-dependent coefiii
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.