Experimental data taken from free-field soil in 1-g shaking table tests are valuable for seismic studies on soil-structure interaction.But the available data from medium-to large-scale shaking table tests were not abu...Experimental data taken from free-field soil in 1-g shaking table tests are valuable for seismic studies on soil-structure interaction.But the available data from medium-to large-scale shaking table tests were not abundant enough to cover a large variety of types and conditions of the soil.In the study,1-g shaking table tests of a 3-m-height sand column were conducted to provide seismic experimental data about sand.The sand was directly collected in-situ,with the largest grain diameter being 2 cm and containing a water content of 6.3%.Properties of the sand were estimated under the influence of white noise plus pulse and earthquake motions,including the settlement,the dynamic properties of the sand column,and the three soil layers′shear modulus degradation relationships.The estimated properties were then indirectly verified by means of finite element analysis.Results show that the estimated parameters were effective and could be used in numerical modeling to reproduce approximate seismic responses of the sand column.展开更多
This article deals with subjective measurements of attenuation characteristic of three earmuffs (A, B, C) and two earplugs (foam and molded). The measurement was carried out through the real-ear attenuation at thresho...This article deals with subjective measurements of attenuation characteristic of three earmuffs (A, B, C) and two earplugs (foam and molded). The measurement was carried out through the real-ear attenuation at threshold (REAT) under freefield condition. The five devices were examined singly, and four of them in combination. The performance of double hearing protection (earplug plus earmuff)were investigated experimentally using the same method for a number of combinations. All tests were conducted on 7 subjects, and two replications per subject. The obtained data of the earmuffs tested show that earmuff (A) posscsses the lowest attenuation and is characterized by highest standard deviation. On the other hand, the foam plug provides the higher attenuation and the lower standard deviation. When the foam plug was combined with either carmuff (B or C) an improvement of attenuation was similar, i. e. the choice of earmuff is not important. This combination yields higher attenuation than that produces for either device alone, but does not simply yield overall attenuation equal to the sum of the individual of each device. However, when situation was reversed, the combination of either earplug (foam or molded) with single earmuff yields variation in attenuation below 2 kHz. At and above 2 kHz, the combination results were comparcd to the bone conduction limits which was reported by different authors. At these frequencies, all tests of plug plus earmuff combinations that were studied provided attenuation approximately equal to the bone conduction limits of human skull. Finally, the attenuation estimates derived in this study werc less than comparable data published by the respective manufacturers.展开更多
Seismic-induced landslides critically threaten infrastructure and human safety,especially in sandy slopes where conventional stabilization methods often fail under dynamic loading.This study evaluates circular open-en...Seismic-induced landslides critically threaten infrastructure and human safety,especially in sandy slopes where conventional stabilization methods often fail under dynamic loading.This study evaluates circular open-ended anti-slide pipe piles embedded in a two-layer sandy slope with differing geotechnical properties.Ten physical models,including five freefield and five pile-reinforced slopes,were tested on a shaking table.Key seismic responses—acceleration,soil displacement,and bending moments—were monitored using accelerometers,strain gauges,and Digital Image Correlation(DIC).Complementary numerical simulations using Abaqus with a Mohr–Coulomb model validated experimental results.Soil displacement in free-field models under 0.25g shaking was about 3.5 times greater than in reinforced slopes.Bending moments increased with seismic intensity,peaking at depths around five times the pile diameter.Limitations including simplified two-layer soil representation,idealized seismic inputs,and boundary effects inherent to laboratory models restrict direct field application but enable controlled analysis.By combining physical experiments with numerical modeling,the study provides a robust and validated framework for seismic slope stabilization.This integrated approach enhances understanding of soil–pile interaction under seismic loads and offers targeted insights for developing safer and more reliable geotechnical design strategies in earthquake-prone areas.展开更多
为探究脱病毒种苗对果蔗的影响,本研究以广东黄皮果蔗为试验材料,进行了自留种、脱毒一代、脱毒二代果蔗种苗的田间性状和果汁品质的比较研究。结果表明,3种材料中,脱毒二代果蔗的田间生长状态最佳,与自留种和脱毒一代相比,其地上株高...为探究脱病毒种苗对果蔗的影响,本研究以广东黄皮果蔗为试验材料,进行了自留种、脱毒一代、脱毒二代果蔗种苗的田间性状和果汁品质的比较研究。结果表明,3种材料中,脱毒二代果蔗的田间生长状态最佳,与自留种和脱毒一代相比,其地上株高分别提高9.08%、5.80%(其中可食部分高度分别提高13.64%、7.19%),茎粗分别提高13.98%、9.71%,产量分别提高47.76%、63.72%(达到159.5 t hm^(-2)),出汁率分别提高3.64%、9.17%,蔗汁的总糖含量分别下降10.14%、12.73%;脱毒对果蔗蔗汁的密度、锤度和纤维含量无显著影响;脱毒苗第一代果蔗与自留种的产量和蔗汁品质无显著差异,脱毒组培苗作为第一代种苗可用于繁育脱毒果蔗种茎,3—4月份适宜移栽。因此,相对于一代组培苗,采用脱毒第二代种苗(脱毒第一代种苗种植收获的果蔗种茎)进行商品蔗种植效果更好,可促进果蔗田间生长,显著提高果蔗的产量。展开更多
基金Supported by:National Natural Science Foundation of China under Grant Nos.52008233 and U1839201the National Key Research and Development Program of China under Grant No.2018YFC1504305the Innovative Research Groups of the National Natural Science Foundation of China under Grant No.51421005。
文摘Experimental data taken from free-field soil in 1-g shaking table tests are valuable for seismic studies on soil-structure interaction.But the available data from medium-to large-scale shaking table tests were not abundant enough to cover a large variety of types and conditions of the soil.In the study,1-g shaking table tests of a 3-m-height sand column were conducted to provide seismic experimental data about sand.The sand was directly collected in-situ,with the largest grain diameter being 2 cm and containing a water content of 6.3%.Properties of the sand were estimated under the influence of white noise plus pulse and earthquake motions,including the settlement,the dynamic properties of the sand column,and the three soil layers′shear modulus degradation relationships.The estimated properties were then indirectly verified by means of finite element analysis.Results show that the estimated parameters were effective and could be used in numerical modeling to reproduce approximate seismic responses of the sand column.
文摘This article deals with subjective measurements of attenuation characteristic of three earmuffs (A, B, C) and two earplugs (foam and molded). The measurement was carried out through the real-ear attenuation at threshold (REAT) under freefield condition. The five devices were examined singly, and four of them in combination. The performance of double hearing protection (earplug plus earmuff)were investigated experimentally using the same method for a number of combinations. All tests were conducted on 7 subjects, and two replications per subject. The obtained data of the earmuffs tested show that earmuff (A) posscsses the lowest attenuation and is characterized by highest standard deviation. On the other hand, the foam plug provides the higher attenuation and the lower standard deviation. When the foam plug was combined with either carmuff (B or C) an improvement of attenuation was similar, i. e. the choice of earmuff is not important. This combination yields higher attenuation than that produces for either device alone, but does not simply yield overall attenuation equal to the sum of the individual of each device. However, when situation was reversed, the combination of either earplug (foam or molded) with single earmuff yields variation in attenuation below 2 kHz. At and above 2 kHz, the combination results were comparcd to the bone conduction limits which was reported by different authors. At these frequencies, all tests of plug plus earmuff combinations that were studied provided attenuation approximately equal to the bone conduction limits of human skull. Finally, the attenuation estimates derived in this study werc less than comparable data published by the respective manufacturers.
基金the support from the Outstanding Youth Foundation of Shandong Province(ZR2021YQ31)the National Natural Science Foundation of China(42277135)+5 种基金National Foreign Experts Individual Program(Category Y)(Grant No.Y20240084)the National Natural Science Foundation of China Joint Fund Key Project(U2006225)Special Fund for Taishan Scholar Projectthe Youth Project of Open Funding from Engineering Research Center of Concrete Technology under Marine Environment,Ministry of Education(Grant No.TMduracon202217)the funding from Key Laboratory of Ministry of Education for Coastal Disaster and Protection,Hohai University(Grant No.202206)Shandong Provincial Overseas High-Level Talent Workstation,China。
文摘Seismic-induced landslides critically threaten infrastructure and human safety,especially in sandy slopes where conventional stabilization methods often fail under dynamic loading.This study evaluates circular open-ended anti-slide pipe piles embedded in a two-layer sandy slope with differing geotechnical properties.Ten physical models,including five freefield and five pile-reinforced slopes,were tested on a shaking table.Key seismic responses—acceleration,soil displacement,and bending moments—were monitored using accelerometers,strain gauges,and Digital Image Correlation(DIC).Complementary numerical simulations using Abaqus with a Mohr–Coulomb model validated experimental results.Soil displacement in free-field models under 0.25g shaking was about 3.5 times greater than in reinforced slopes.Bending moments increased with seismic intensity,peaking at depths around five times the pile diameter.Limitations including simplified two-layer soil representation,idealized seismic inputs,and boundary effects inherent to laboratory models restrict direct field application but enable controlled analysis.By combining physical experiments with numerical modeling,the study provides a robust and validated framework for seismic slope stabilization.This integrated approach enhances understanding of soil–pile interaction under seismic loads and offers targeted insights for developing safer and more reliable geotechnical design strategies in earthquake-prone areas.
文摘为探究脱病毒种苗对果蔗的影响,本研究以广东黄皮果蔗为试验材料,进行了自留种、脱毒一代、脱毒二代果蔗种苗的田间性状和果汁品质的比较研究。结果表明,3种材料中,脱毒二代果蔗的田间生长状态最佳,与自留种和脱毒一代相比,其地上株高分别提高9.08%、5.80%(其中可食部分高度分别提高13.64%、7.19%),茎粗分别提高13.98%、9.71%,产量分别提高47.76%、63.72%(达到159.5 t hm^(-2)),出汁率分别提高3.64%、9.17%,蔗汁的总糖含量分别下降10.14%、12.73%;脱毒对果蔗蔗汁的密度、锤度和纤维含量无显著影响;脱毒苗第一代果蔗与自留种的产量和蔗汁品质无显著差异,脱毒组培苗作为第一代种苗可用于繁育脱毒果蔗种茎,3—4月份适宜移栽。因此,相对于一代组培苗,采用脱毒第二代种苗(脱毒第一代种苗种植收获的果蔗种茎)进行商品蔗种植效果更好,可促进果蔗田间生长,显著提高果蔗的产量。
