International Journal of Physical Modelling in Geotechnics最新文献_第3页

Mitigating Liquefaction-Induced Displacements of Shallow Foundation using Helical Piles 螺旋桩减轻浅基础液化引起的位移

IF 1.9 4区工程技术

International Journal of Physical Modelling in Geotechnics Pub Date : 2022-06-06 DOI: 10.1680/jphmg.21.00039

P. Esmaeilpour, Y. Jafarian, A. Cerato

{"title":"Mitigating Liquefaction-Induced Displacements of Shallow Foundation using Helical Piles","authors":"P. Esmaeilpour, Y. Jafarian, A. Cerato","doi":"10.1680/jphmg.21.00039","DOIUrl":"https://doi.org/10.1680/jphmg.21.00039","url":null,"abstract":"During previous earthquakes, displacements of shallow foundations on liquefiable sites caused significant damage to overlying super-structures leading to casualties and catastrophic economic loss. Various countermeasures have been developed to minimize liquefaction-related damages while minimizing cost and environmental impact. This study aims to evaluate the use of helical piles as a possible technique to mitigate the settlement, tilting, and sliding of shallow foundations on the liquefiable ground in seismic conditions. For this purpose, twelve 1g shaking table tests were conducted on uniform loose saturated Babolsar sand subjected to harmonic base input motion for (1) free-field condition, (2) a model foundation on the soil surface, and (3) a model foundation underpinned by helical piles. The effects of input motion amplitudes and the number of helical piles were investigated in terms of acceleration response, excess pore water pressure (EPWP), and foundation displacements. The results confirmed the satisfactory performance of helical piles in reducing shallow foundation displacements. In particular, the mean permanent settlements were reduced by 45% and 75% when using four and eight helical piles, respectively. Similar trends were observed for the shallow foundation permanent tilting and sliding; permanent tilting was reduced by 30% and 59% when using four and eight helical piles, respectively, while these results were 45% and 68% for the sliding.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42754865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Design and Instrumentation of a Novel Centrifuge Container for Fly Ash Run-out Experiments 新型飞灰跳动实验离心容器的设计与仪器

IF 1.9 4区工程技术

International Journal of Physical Modelling in Geotechnics Pub Date : 2022-06-06 DOI: 10.1680/jphmg.21.00044

S. Madabhushi, A. Martínez, D. Wilson, B. Kutter

{"title":"Design and Instrumentation of a Novel Centrifuge Container for Fly Ash Run-out Experiments","authors":"S. Madabhushi, A. Martínez, D. Wilson, B. Kutter","doi":"10.1680/jphmg.21.00044","DOIUrl":"https://doi.org/10.1680/jphmg.21.00044","url":null,"abstract":"Debris flow, landslides and material run-outs have significant environmental and economic consequences for numerous industries. High quality experimental data with controlled boundary conditions can help validate and calibrate the predictive capabilities of mechanistic and semi-empirical numerical models. A novel centrifuge container to model dewatering and run-outs induced by a rapid loss of confinement is presented. The design features a pair of vertical doors opened in-flight to simulate failure of the containing structure. Illustrative centrifuge results investigating the run-out characteristics of a fully saturated, densely deposited class-F fly ash are presented. Modified soil moisture probes to monitor the distributions and time-varying fly ash water content throughout the testing are explored. Further, successful use of depth sensing cameras to reconstruct progressive deformations of the material front at various time scales is demonstrated. Combined water content, pore pressure and deformation measurements provides insight into the material behaviour during the run-out, revealing two-time scales at which the deformations occur. However, discrepancies between water contents inferred from the dielectric measurements and electrical conductivities highlights the need for independent verification of the bulk material water content when using the modified probes. Overall, the potential of these innovative instrumentation techniques to complement traditional geotechnical instrumentation is shown.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43315537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Reduction of footprint problems on spudcan in sand with infilling method 用充填法减少铲泥在砂土中的足迹问题

IF 1.9 4区工程技术

International Journal of Physical Modelling in Geotechnics Pub Date : 2022-05-13 DOI: 10.1680/jphmg.21.00066

Yu Fang, Ying-Chu Shih, Cheng Liu, Jyun-Yi Hsieh

{"title":"Reduction of footprint problems on spudcan in sand with infilling method","authors":"Yu Fang, Ying-Chu Shih, Cheng Liu, Jyun-Yi Hsieh","doi":"10.1680/jphmg.21.00066","DOIUrl":"https://doi.org/10.1680/jphmg.21.00066","url":null,"abstract":"This paper presents experimental data associated with the reactions on the spudcan during the reinstallation of a jack-up foundation near a footprint with and without infilling. All experiments mentioned in this paper were conducted in a 1-g model spudcan testing facility. Loose Ottawa sand was used as the seabed and infilling material, and the diameter D of the conical model spudcan was 200 mm. Based on the experimental data, it was found that, with the infilling of the footprint crater, a flat bearing surface was generated on the seabed, therefore the hazardous stamp-on-void situation was prevented. This was the major contribution of the infilling method. At the small reinstallation depth of 0.05D, between the small offsets 0 and 0.25D, the stamp-on-void condition was eliminated by infilling, and the infilling effect was especially significant. At the large offset 2.0D, since the reinstallation was conducted far from the influence of the first penetration and the footprint crater, therefore the infilling effect nearly vanished. The effect of infilling decreased with increasing reinstallation depth and increasing offset distance.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48631359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Editorial 社论

IF 1.9 4区工程技术

International Journal of Physical Modelling in Geotechnics Pub Date : 2022-05-01 DOI: 10.1680/jphmg.2022.22.3.111

Conleth D. O'Loughlin

引用次数: 0

Boundary effects on dynamic centrifuge modelling of onshore wind turbines on liquefiable soils 可液化土壤上陆上风力发电机动态离心模型的边界效应

IF 1.9 4区工程技术

International Journal of Physical Modelling in Geotechnics Pub Date : 2022-04-11 DOI: 10.1680/jphmg.21.00085

D. Gaudio, J. Seong, S. Haigh, Giulia M. B. Viggiani, G. Madabhushi, R. Shrivatsava, Ravikant Veluvolu, P. Padhy

{"title":"Boundary effects on dynamic centrifuge modelling of onshore wind turbines on liquefiable soils","authors":"D. Gaudio, J. Seong, S. Haigh, Giulia M. B. Viggiani, G. Madabhushi, R. Shrivatsava, Ravikant Veluvolu, P. Padhy","doi":"10.1680/jphmg.21.00085","DOIUrl":"https://doi.org/10.1680/jphmg.21.00085","url":null,"abstract":"Centrifuge modelling is an effective tool to assess the response of reduced-scale structures subjected to earthquakes under increased gravity. Space limitations, however, force the model to be contained within relatively small boxes, whose boundaries may affect the seismic performance of the structure under consideration. In this paper, the influence of the proximity of the boundaries of an Equivalent Shear Beam (ESB) container during dynamic centrifuge tests of an onshore wind turbine resting on liquefiable soils is evaluated. To this end, numerical modelling of the ESB box was implemented in the Finite Element framework OpenSees, to replicate the results observed in the experiment. The hydraulic and mechanical soil parameters were calibrated against far-field centrifuge results only. From this calibration, the seismic performance of the raft foundation turned out to be in a good agreement with the experimental results for a seismic input capable of triggering liquefaction. A larger numerical model, where boundaries do not play any role, was then built, to compare its outcomes with those of the small model, thus allowing the effect of ESB boundaries to be assessed.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44609938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Investigation of a laboratory-based approach to determine ageing of shaft friction of piles in clay 基于实验室的方法测定粘土中桩身摩擦老化的研究

IF 1.9 4区工程技术

International Journal of Physical Modelling in Geotechnics Pub Date : 2022-03-24 DOI: 10.1680/jphmg.21.00016

Bin Huang, B. Lehane, P. Watson

{"title":"Investigation of a laboratory-based approach to determine ageing of shaft friction of piles in clay","authors":"Bin Huang, B. Lehane, P. Watson","doi":"10.1680/jphmg.21.00016","DOIUrl":"https://doi.org/10.1680/jphmg.21.00016","url":null,"abstract":"The shaft capacity of driven piles in clay increases with time even after installation-induced consolidation is completed. However, existing studies have shown that these gains in capacity are variable and cannot be predicted reliably. Projects such as those involving life extension of existing offshore platforms (which often involve increased platform loads) as well as those considering foundation re-use provide the motivation for this paper, which investigates the potential for model scale testing to replicate the ageing characteristic of shaft friction in a laboratory environment. The study employs a number of model piles installed in reconstituted, high plasticity Onsoy clay in laboratory pressure chambers. The first time tension load tests on these piles, performed over the period of 1 year after installation, are compared with a similar series of tests on full-scale driven piles in Onsoy, Norway. Good agreement between laboratory and field experiments is observed when allowance is made for the significantly longer consolidation periods of the full-scale piles. This finding implies that ageing effects of shaft friction in clay can be investigated over relatively short time periods using model piles in laboratory testing chambers.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43591545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Experimental studies on a circular open caisson 圆形开式沉箱的试验研究

IF 1.9 4区工程技术

International Journal of Physical Modelling in Geotechnics Pub Date : 2022-03-16 DOI: 10.1680/jphmg.20.00050

Jitesh T. Chavda, Goudappa R. Dodagoudar

引用次数: 3

The Effects of Voids on the Dynamic Response of Tunnels Under Train Induced Vibration Loads 列车诱导振动荷载作用下空隙对隧道动力响应的影响

IF 1.9 4区工程技术

International Journal of Physical Modelling in Geotechnics Pub Date : 2022-03-04 DOI: 10.1680/jphmg.21.00023

Wen-bo Yang, Gaoyu Ma, J. Tu, Hao Kou, Yanyang Zhang, Yong Fang, Chuan He

{"title":"The Effects of Voids on the Dynamic Response of Tunnels Under Train Induced Vibration Loads","authors":"Wen-bo Yang, Gaoyu Ma, J. Tu, Hao Kou, Yanyang Zhang, Yong Fang, Chuan He","doi":"10.1680/jphmg.21.00023","DOIUrl":"https://doi.org/10.1680/jphmg.21.00023","url":null,"abstract":"This paper presents results of the voids influences on the dynamic response of tunnel linings and surrounding strata acquired in series of model tests. An experimental model of a tunnel was tested with a void of varying size (ratio of void width to tunnel diameter of 0.13, 0.27, and 0.4) and location (at tunnel apex, haunch and invert). During the tests, the tunnel invert were applied with three types of vibration loads: a sinusoidal load with a fixed frequency, a sinusoidal sweep load, and a simulated train load. The tunnel lining and soil response were recorded by accelerometers, with analysis results presented in both time and frequency domain. The experimental results manifest that the voids can have a distinct influence on the tunnel and soil dynamic response, with a clear amplification of tunnel and soil response for certain cases. The test results also demonstrate that the tunnel and soil response are sensitive to the void size and location in the near field. However, with increased distance from the excitation source, the void effects on the tunnel and soil dynamic response gradually declines.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43145833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Response of a Model Footing Reinforced by Novel Three Dimensional Elements 新型三维单元加固模型基础的响应

IF 1.9 4区工程技术

International Journal of Physical Modelling in Geotechnics Pub Date : 2022-02-22 DOI: 10.1680/jphmg.21.00055

S. N. Moghaddas Tafreshi, N. Karami, M. Rahimi, A. R. Dawson

{"title":"Response of a Model Footing Reinforced by Novel Three Dimensional Elements","authors":"S. N. Moghaddas Tafreshi, N. Karami, M. Rahimi, A. R. Dawson","doi":"10.1680/jphmg.21.00055","DOIUrl":"https://doi.org/10.1680/jphmg.21.00055","url":null,"abstract":"In this study, a new three-dimensional (3D) reinforcement element comprising a horizontal ring connected to the vertical legs is introduced. A series of 1g laboratory scale tests were conducted on a circular footing that rested on a sand bed containing planar or new 3D-reinforcements. The effects of depth of first layer, reinforcements configuration number and spacing of layers are reported. Tests were performed on both discrete or contiguously attached elements. The new 3D elements were examined with either upward- or downward-facing legs. An improvement of about 16% was achieved by the upward-legged contiguous 3D elements over the performance delivered by planar contiguous elements. Also, results show that the vertical legs are capable of exerting passive forces on the soil and increasing the stiffness and bearing capacity of the composite system, but the contributory effect is more pronounced for the upward-leg configuration. Finally, 17% and 26% improvements were achieved, respectively, for two planar and two 3D-reinforcement layers when compared with that of a single layer. The concept of planar reinforcement connected to vertical legs, could be adapted for developing a more efficient generation of reinforcement, such as geogrids with vertical ‘legs’, to take advantage of the passive resistance generated by ‘legs’.","PeriodicalId":48816,"journal":{"name":"International Journal of Physical Modelling in Geotechnics","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44352745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Measuring Vertical Displacement Using Laser Lines and Cameras 使用激光线和相机测量垂直位移

IF 1.9 4区工程技术

International Journal of Physical Modelling in Geotechnics Pub Date : 2021-10-18 DOI: 10.1680/jphmg.21.00038

S. Sinha, B. Kutter, K. Ziotopoulou

引用次数: 2