In 2023,pivotal advancements in artificial intelligence(AI)have significantly experienced.With that in mind,traditional methodologies,notably the p-y approach,have struggled to accurately model the complex,nonlinear s...In 2023,pivotal advancements in artificial intelligence(AI)have significantly experienced.With that in mind,traditional methodologies,notably the p-y approach,have struggled to accurately model the complex,nonlinear soil-structure interactions of laterally loaded large-diameter drilled shafts.This study undertakes a rigorous evaluation of machine learning(ML)and deep learning(DL)techniques,offering a comprehensive review of their application in addressing this geotechnical challenge.A thorough review and comparative analysis have been carried out to investigate various AI models such as artificial neural networks(ANNs),relevance vector machines(RVMs),and least squares support vector machines(LSSVMs).It was found that despite ML approaches outperforming classic methods in predicting the lateral behavior of piles,their‘black box'nature and reliance only on a data-driven approach made their results showcase statistical robustness rather than clear geotechnical insights,a fact underscored by the mathematical equations derived from these studies.Furthermore,the research identified a gap in the availability of drilled shaft datasets,limiting the extendibility of current findings to large-diameter piles.An extensive dataset,compiled from a series of lateral loading tests on free-head drilled shaft with varying properties and geometries,was introduced to bridge this gap.The paper concluded with a direction for future research,proposes the integration of physics-informed neural networks(PINNs),combining data-driven models with fundamental geotechnical principles to improve both the interpretability and predictive accuracy of AI applications in geotechnical engineering,marking a novel contribution to the field.展开更多
The development of experimental facilities for rail vehicle testing at the NRCCentre for Surface Transportation Technology is being complemented byanalytic studies. The purpose of this effort has been to gain insight ...The development of experimental facilities for rail vehicle testing at the NRCCentre for Surface Transportation Technology is being complemented byanalytic studies. The purpose of this effort has been to gain insight into thedynamics of rail vehicles in order to guide the development of the Curved TrackSimulator (CTS) and to establish an analytic framework for the design andinterpretation of tests to be conducted on the CTS. The work described hererepresents an initial effort towarde meeting these objectives.Parametric study results using linear model of freight truck on the CTSshowed that (a) increasing roller radius increases critical speed (b) increasingthe wheel initial cone angle will decrease the hunting speed (c) increasing theroller cant increases hunting speed (d) decrowning of the wheelset on the rollerewill not effect the hunting speed but induces longitudinal destabilzing horizontalforces at the contact and (e) lozenging of wheelset on the rollers induces a yawmoment and the hunting speed decreases with increasing wheelset yaw angle.展开更多
With the high-quality development of urban buildings,higher requirements are come up with for lateral bearing capacity of laterally loaded piles.Consequently,a more accurate analysis to predict the lateral response of...With the high-quality development of urban buildings,higher requirements are come up with for lateral bearing capacity of laterally loaded piles.Consequently,a more accurate analysis to predict the lateral response of the pile within an allowable displacement is an important issue.However,the current p-y curve methods cannot fully take into account the pile-soil interaction,which will lead to a large calculation difference.In this paper,a new analytical p-y curve is established and a finite difference method for determining the lateral response of pile is proposed,which can consider the separation effect of pile-soil interface and the coefficient of circumferential friction resistance.In particular,an analytical expression is developed to determine the compressive soil pressure by dividing the compressive soil pressure into two parts:initial compressive soil pressure and increment of compressive soil pressure.In addition,the relationship between compressive soil pressure and horizontal displacement of the pile is established based on the reasonable assumption.The correctness of the proposed method is verified through four examples.Based on the verified method,a parametric analysis is also conducted to investigate the influences of factors on lateral response of the pile,including internal friction angle,pile length and elastic modulus of pile.展开更多
After introducing the theories parabola （FDP）, half-wave-length length, offset and the maximum of acceleration （LCA）, the SI curve, and geometric features of four familiar transition curves （cubic parabola （CP）...After introducing the theories parabola （FDP）, half-wave-length length, offset and the maximum of acceleration （LCA）, the SI curve, and geometric features of four familiar transition curves （cubic parabola （CP）, fifth degree sinusoidal （HS） and sinusoidal （SI）） , these curves are compared under identical conditions of the first derivative of curvature. In terms of the roll acceleration （RA） and the lateral change of in theory, is superior to other transition curves.展开更多
A cylindrical negative Poisson's ratio(CNPR) structure based on two-dimensional double-arrow negative Poisson's ratio(NPR)structure was introduced in this paper. The CNPR structure has excellent stiffness, dam...A cylindrical negative Poisson's ratio(CNPR) structure based on two-dimensional double-arrow negative Poisson's ratio(NPR)structure was introduced in this paper. The CNPR structure has excellent stiffness, damping and energy absorption performances,and can be applied as spring, damper and energy absorbing components. In this study, the CNPR structure was used as a jounce bumper in vehicle suspension, and the load-displacement curve of NPR jounce bumper was discussed. Moreover, the influences of structural parameters and materials on the load-displacement curve of NPR jounce bumper were specifically researched. It came to the conclusion that only the numbers of cells and layers impact the hardening displacement of NPR jounce bumper. And all parameters significantly affect the structure stiffness at different displacement periods. On the other hand, the load-displacement curve of NPR jounce bumper should be in an ideal region which is difficult to be achieved applying mathematical optimization method. Therefore, a parametric design strategy of NPR jounce bumper was proposed according to the parametric analysis results. The design strategy had two main steps: design of hardening displacement and design of stiffness. The analysis results proved that the proposed method is reliable and is also meaningful for relevant structure design problem.展开更多
This paper presents a proposed concept of a spiraled roadside curve for determining the required lateral clearance that satisfies sight distance needs on a roadway reverse hori- zontal curve. The spiraled roadside cur...This paper presents a proposed concept of a spiraled roadside curve for determining the required lateral clearance that satisfies sight distance needs on a roadway reverse hori- zontal curve. The spiraled roadside curve was evaluated in the context of roadway plan view. The characteristics of its corresponding lateral offsets were analyzed. It was found that the ratio of the radii for the two reversing circular curves was the major factor that impacted the ratio of the required offset to the maximum offset of a circular curve. A single design chart and a design table were developed. The required offsets at alignment reversing sections were far less than those recommended by the American Association of State Highways and Transportation Officials （AASHTO） and those required at the approach and departure sections of a roadway simple curve. At the common point of the two reversing circular curves having a radius ratio R2/R1 ranging from 0.5 to 2, the required offsets were approximately 34%-66% of the maximum offsets recommended by AASHTO and approximately 41%-79% of those required in the case of a simple curve. The engi- neering implications of the proposed spiraled roadside curve are multifold： （a） it can be designed in a way similar to traditional roadway design, （b） it avoided the application of numerous design charts and extensive computations, （c） it can be easily staked on the field, （d） it not only greatly improved the A_ASHTO approximate approach, but also improved roadway design consistency.展开更多
基金supported by Prince Sultan University(Grant No.PSU-CE-TECH-135,2023).
文摘In 2023,pivotal advancements in artificial intelligence(AI)have significantly experienced.With that in mind,traditional methodologies,notably the p-y approach,have struggled to accurately model the complex,nonlinear soil-structure interactions of laterally loaded large-diameter drilled shafts.This study undertakes a rigorous evaluation of machine learning(ML)and deep learning(DL)techniques,offering a comprehensive review of their application in addressing this geotechnical challenge.A thorough review and comparative analysis have been carried out to investigate various AI models such as artificial neural networks(ANNs),relevance vector machines(RVMs),and least squares support vector machines(LSSVMs).It was found that despite ML approaches outperforming classic methods in predicting the lateral behavior of piles,their‘black box'nature and reliance only on a data-driven approach made their results showcase statistical robustness rather than clear geotechnical insights,a fact underscored by the mathematical equations derived from these studies.Furthermore,the research identified a gap in the availability of drilled shaft datasets,limiting the extendibility of current findings to large-diameter piles.An extensive dataset,compiled from a series of lateral loading tests on free-head drilled shaft with varying properties and geometries,was introduced to bridge this gap.The paper concluded with a direction for future research,proposes the integration of physics-informed neural networks(PINNs),combining data-driven models with fundamental geotechnical principles to improve both the interpretability and predictive accuracy of AI applications in geotechnical engineering,marking a novel contribution to the field.
文摘The development of experimental facilities for rail vehicle testing at the NRCCentre for Surface Transportation Technology is being complemented byanalytic studies. The purpose of this effort has been to gain insight into thedynamics of rail vehicles in order to guide the development of the Curved TrackSimulator (CTS) and to establish an analytic framework for the design andinterpretation of tests to be conducted on the CTS. The work described hererepresents an initial effort towarde meeting these objectives.Parametric study results using linear model of freight truck on the CTSshowed that (a) increasing roller radius increases critical speed (b) increasingthe wheel initial cone angle will decrease the hunting speed (c) increasing theroller cant increases hunting speed (d) decrowning of the wheelset on the rollerewill not effect the hunting speed but induces longitudinal destabilzing horizontalforces at the contact and (e) lozenging of wheelset on the rollers induces a yawmoment and the hunting speed decreases with increasing wheelset yaw angle.
基金Project(52068004)supported by the National Natural Science Foundation of ChinaProject(2018JJA160134)supported by the Natural Science Foundation of Guangxi Province,ChinaProject(AB19245018)supported by Key Research Projects of Guangxi Province,China。
文摘With the high-quality development of urban buildings,higher requirements are come up with for lateral bearing capacity of laterally loaded piles.Consequently,a more accurate analysis to predict the lateral response of the pile within an allowable displacement is an important issue.However,the current p-y curve methods cannot fully take into account the pile-soil interaction,which will lead to a large calculation difference.In this paper,a new analytical p-y curve is established and a finite difference method for determining the lateral response of pile is proposed,which can consider the separation effect of pile-soil interface and the coefficient of circumferential friction resistance.In particular,an analytical expression is developed to determine the compressive soil pressure by dividing the compressive soil pressure into two parts:initial compressive soil pressure and increment of compressive soil pressure.In addition,the relationship between compressive soil pressure and horizontal displacement of the pile is established based on the reasonable assumption.The correctness of the proposed method is verified through four examples.Based on the verified method,a parametric analysis is also conducted to investigate the influences of factors on lateral response of the pile,including internal friction angle,pile length and elastic modulus of pile.
基金The National Natural Science Foundation of China(No.50878134)the Natural Science Foundation of Hebei Province(No.E2006000394)the Natural Science Foundation of Hebei Education Department(No.2006142)
文摘After introducing the theories parabola （FDP）, half-wave-length length, offset and the maximum of acceleration （LCA）, the SI curve, and geometric features of four familiar transition curves （cubic parabola （CP）, fifth degree sinusoidal （HS） and sinusoidal （SI）） , these curves are compared under identical conditions of the first derivative of curvature. In terms of the roll acceleration （RA） and the lateral change of in theory, is superior to other transition curves.
基金supported by the Natural Science Foundation of Jiangsu Province(Grant No.BK20170784)Aeronautical Science Foundation of China(Granted No.2016ZA52003)
文摘A cylindrical negative Poisson's ratio(CNPR) structure based on two-dimensional double-arrow negative Poisson's ratio(NPR)structure was introduced in this paper. The CNPR structure has excellent stiffness, damping and energy absorption performances,and can be applied as spring, damper and energy absorbing components. In this study, the CNPR structure was used as a jounce bumper in vehicle suspension, and the load-displacement curve of NPR jounce bumper was discussed. Moreover, the influences of structural parameters and materials on the load-displacement curve of NPR jounce bumper were specifically researched. It came to the conclusion that only the numbers of cells and layers impact the hardening displacement of NPR jounce bumper. And all parameters significantly affect the structure stiffness at different displacement periods. On the other hand, the load-displacement curve of NPR jounce bumper should be in an ideal region which is difficult to be achieved applying mathematical optimization method. Therefore, a parametric design strategy of NPR jounce bumper was proposed according to the parametric analysis results. The design strategy had two main steps: design of hardening displacement and design of stiffness. The analysis results proved that the proposed method is reliable and is also meaningful for relevant structure design problem.
基金supported by a Discovery Grant 1-51-52657 (131033) Discovery-Accelerator Grant 1-51-52687(131871) from the Natural Sciences and Engineering Research Council of Canada
文摘This paper presents a proposed concept of a spiraled roadside curve for determining the required lateral clearance that satisfies sight distance needs on a roadway reverse hori- zontal curve. The spiraled roadside curve was evaluated in the context of roadway plan view. The characteristics of its corresponding lateral offsets were analyzed. It was found that the ratio of the radii for the two reversing circular curves was the major factor that impacted the ratio of the required offset to the maximum offset of a circular curve. A single design chart and a design table were developed. The required offsets at alignment reversing sections were far less than those recommended by the American Association of State Highways and Transportation Officials （AASHTO） and those required at the approach and departure sections of a roadway simple curve. At the common point of the two reversing circular curves having a radius ratio R2/R1 ranging from 0.5 to 2, the required offsets were approximately 34%-66% of the maximum offsets recommended by AASHTO and approximately 41%-79% of those required in the case of a simple curve. The engi- neering implications of the proposed spiraled roadside curve are multifold： （a） it can be designed in a way similar to traditional roadway design, （b） it avoided the application of numerous design charts and extensive computations, （c） it can be easily staked on the field, （d） it not only greatly improved the A_ASHTO approximate approach, but also improved roadway design consistency.
