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Fabrication of a highly efficient new nanocomposite polymer gel for controlling the excess water production in petroleum reservoirs and increasing the performance of enhanced oil recovery processes
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作者 Sajad Asadizadeh Shahab Ayatollahi Bahman ZareNezhad 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第4期385-392,共8页
A new nanocomposite polymer gel is synthesized for reduction of excess water production in petroleum reservoirs at real operating conditions.This new nanocomposite gel contains SiO2 nanoparticles,partially hydrolyzed ... A new nanocomposite polymer gel is synthesized for reduction of excess water production in petroleum reservoirs at real operating conditions.This new nanocomposite gel contains SiO2 nanoparticles,partially hydrolyzed polyacrylamide(HPAM)and chromium triacetate.High pressure and high temperature tests using porous carbonate core are carried out to evaluate the effects of nanoparticles on the synthesized polymer gel performance.It is shown that the residual resistance factor ratio of water to oil using the synthesized polymer gel nanocomposite in this work is much higher than that of the ordinary polymer gels.The presented results confirm the high performance of the synthesized nanocomposite polymer gel for decreasing the water flow through porous carbonate bed.A mathematical model for description of oil and water flow behavior in the presence of synthesized nanocomposite polymer gel is also presented.The presented nano polymer gel leads to considerable cost saving in enhanced oil recovery(EOR)processes. 展开更多
关键词 PETROLEUM excess water NANOCOMPOSITE Polymer gel Nanoparticle EOR
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Effects of Terrain Morphology Model on Excess Water Inundation and Phosphorus Transport Modeling
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作者 Zsolt Jolankai Laszlo Koncsos 《Journal of Environmental Science and Engineering(B)》 2013年第12期728-735,共8页
An integrated hydrological model has been applied for a rural-urban catchment of the Szamos-Kraszna interfluve geographic area, using the WateRisk integrated hydrological model system. The aim of the hydrological simu... An integrated hydrological model has been applied for a rural-urban catchment of the Szamos-Kraszna interfluve geographic area, using the WateRisk integrated hydrological model system. The aim of the hydrological simulations was to identify the role that the relief plays in the water coverage formation process, and to highlight the possible consequences of it on phosphorus transport processes. To support this aim, the rainfall-runoff and the one-dimensional flow routing modules have been modelled, and maximal water cover has been calculated. Measured water coverage data by remote sensing have been compared to calculated maximum water cover in several ways. Results support the existing perspective on excess water formation namely that the process is very complex, therefore, the coincidence of the locations of measured water cover with calculated maximum water cover based on the DEM (digital elevation model) and the river network is low. Analysis shows that as far as the larger depressions of the area are concerned, the error of the DEM is not high, but it is likely that at locations with small altitude differences, the error of DEM can cause larger errors. The results foreshadow the importance of the micro relief of the area on phosphorus transport. 展开更多
关键词 Hydrological modeling terrain morphology excess water inundation water coverage phosphorus transport.
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Methodological Issues for a Landscape-Changing Analysis in Adaptive Excess Water Management
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作者 Dalma Varga Nora Hubayne Horvath 《Journal of Agricultural Science and Technology(A)》 2021年第2期65-74,共10页
Hungary is located in the deepest part of the Pannonian Basin,which is affected by floodwaters.Lowland areas are particularly vulnerable to floods.Many natural and anthropogenic processes have contributed to the forma... Hungary is located in the deepest part of the Pannonian Basin,which is affected by floodwaters.Lowland areas are particularly vulnerable to floods.Many natural and anthropogenic processes have contributed to the formation of these flood patches,after river regulation(decisively from the middle of 18th century)and continue to affect them.The objective of this research is to reveal the processes of landscape-change in areas of waterlogging,or areas threatened by excess water inundation in order to establish methods of adaptive excess water management.The analysis focuses on examining the previously prevalent land-use structure and linear infrastructure elements(green,blue infrastructures)of the past 200-250 years that can be identified using historical,military maps and aerial photos.Historical maps compare different periods of 50-60 years prevalence.As a result of this analysis,the role of watercourses in shaping landscapes and human intervention process can be monitored and supported with maps including data.The processing consisted of geographic information system(GIS)methods:georeference the historical maps and digitalize the well-separable land-uses of the sample area.The results confirmed the process of landscape-change and the trend of green areas:cultivated areas and the spread of settlements.In conclusion,landscape-changing analyses of landscape-changes provide valuable data onto identifying changes in land-use,which are complemented by hydrological databases,especially those related to waterlogging areas,as they adequately support adaptive excess water management methods in areas with specific characteristics.The results show which land-uses can be considered as permanent,stable land-uses in the given sample area and broach whether changes within the green and blue infrastructure network contribute to the increase or decrease of excess water formation. 展开更多
关键词 Green infrastructure landscape-changing processes excess water historical maps GIS river regulations anthropogenic interference
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Initial excess pore water pressures induced by tunnelling in soft ground 被引量:2
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作者 梁荣柱 夏唐代 +2 位作者 林存刚 俞峰 吴世明 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第11期4300-4309,共10页
Tunnelling-induced long-term consolidation settlement attracts a great interest of engineering practice. The distribution and magnitude of tunnelling-induced initial excess pore water pressure have significant effects... Tunnelling-induced long-term consolidation settlement attracts a great interest of engineering practice. The distribution and magnitude of tunnelling-induced initial excess pore water pressure have significant effects on the long-term consolidation settlement. A simple and reliable method for predicting the tunnel-induced initial excess pore water pressure calculation in soft clay is proposed. This method is based on the theory of elasticity and SKEMPTON's excess pore water pressure theory. Compared with the previously published field measurements and the finite-element modelling results, it is found that the suggested initial excess pore water pressure theory is in a good agreement with the measurements and the FE results. A series of parametric analyses are also carried out to investigate the influences of different factors on the distribution and magnitude of the initial excess pore water pressure in soft ground. 展开更多
关键词 INITIAL excess PORE water PRESSURE geostress relie
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The crystal change and "excess heat" produced by long time electrolysis of heavy water with titanium cathode
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作者 SUN Yue, ZHANG Qing-fu, GOU Qing-quan (Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China) 《原子与分子物理学报》 CAS CSCD 北大核心 2003年第1期69-74,共6页
According to the theory given in the paper , the long time electrolysis experiment with titanium cathode in heavy water (D 2O) were done for many times by using the open-loop multi-parameters electrolysis calorimetry ... According to the theory given in the paper , the long time electrolysis experiment with titanium cathode in heavy water (D 2O) were done for many times by using the open-loop multi-parameters electrolysis calorimetry system, which is established by us. The specialty is that the cathode is titanium rod and the anode is platinum wire. The early experiment result is still repeated in our recent experiment. The obvious "excess heat" phenomenon can take place only when the electrolysis last more than ten days and amount of "excess heat" increased with the electrolysis time. The "excess heat" can also be obtained from the "boiling to dry" experiment. In the recent experiment, we obtain the results that the amount of "excess heat" is about 3.6 times the input energy, the "excess heat" power is 76.5 W, and the "excess heat" power density is 121.7 W/cm 3. After the electrolysis, the crystal structure of the Ti cathode was measured with x-ray diffraction apparatus. We found that the crystal structure of Ti cathode was changed to face-centered cubic structure of TiD 2 from its hexagonal structure. This result is in agreement with the Gou’s theory mentioned in reference . 展开更多
关键词 重水 电解实验 热力学 物态变化 晶体结构 热量测定 原子核物理 聚变
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Identifying Factors Which Contribute to the Magnitude of Excess Correlations between Magnetic Field-Paired Volumes of Water
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作者 Nicolas Rouleau Trevor N. Carniello Michael A. Persinger 《Journal of Signal and Information Processing》 2016年第3期136-147,共13页
Excess correlations, one of the quantitative demonstrations of “entanglement”, have been experimentally demonstrated as spontaneous shifts in photon properties and molecular interactions. The magnitudes of the exces... Excess correlations, one of the quantitative demonstrations of “entanglement”, have been experimentally demonstrated as spontaneous shifts in photon properties and molecular interactions. The magnitudes of the excess correlations have been enhanced experimentally for photon emissions and proton densities in aqueous solutions when the loci containing these physical chemical reactions shared circular magnetic fields whose angular velocities were always changing. In the present experiment, quantities of spring water each placed in one of two loci (local or non-local) separated by 100 or 10,000 m were exposed simultaneously to toroidal magnetic fields within a paradigm that has been shown to produce conspicuous excess correlations in shifts of photon emissions, pH in spring water, and human brain activity as inferred by electroencephalography. The non-local area that was not injected with proton donors displayed a reliable shift in pH when the local area was serially injected with small aliquots of protons but only during the presentations of the field parameters known to produce “entanglement”. The effect was most obvious when the global geomagnetic activity was less than Kp < 3. The probability is high that convergent similarities in the magnitudes of the local geomagnetic intensities of the two loci enhance the strength of the excess correlations. These results suggest that a minimal energy and inexpensive system, not involving classical electromagnetic transmission through a medium, but influenced by the global geomagnetic field activity, could be employed to generalize and superpose information between two non-local spaces. 展开更多
关键词 excess Correlation water TOROIDS Geomagnetic Activity Signal Detection
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Impacts of Excessive Soaking on N, P, and K in Substrates Plots and Seedling Growth
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作者 王甲辰 左强 +4 位作者 谷佳林 肖强 邹国元 张琳 王美菊 《Agricultural Science & Technology》 CAS 2012年第1期158-161,180,共5页
[Objective] The aim was to study on impacts of excessive soaking N, P, and K insubstrate plots of and seedling growth. [Method] Substrate was designed to add additional 1/2 water after saturation and expansion. Dispos... [Objective] The aim was to study on impacts of excessive soaking N, P, and K insubstrate plots of and seedling growth. [Method] Substrate was designed to add additional 1/2 water after saturation and expansion. Disposable excessive soak- ing and regression relation of nutrition infusion of substrate plots were studied by design of 13 time gradient. Plant nutrition absorption and growth effects after sub- strate plots immersed by water were investigated by growing tomato. [Result] Con- centration and time of the three nutrition immersed in water had the regression equation of each, as follows: N=-2E-05t2+0.016 lt+2.0553, P=0.002 2t+2.248 5 and K=0.004 7t+0.875 8. With nutrition loss of the three, however, loss amount was al- most same with variance analysis of regression equation, which may result from its volatilization. Regression equations of P and K were: P=0.125 7t-0.117, and K=0.022 5t.1514, which led to adverse impact on plant absorption of N and K above ground, whose equations were N=20.64e-4E-0.4t, and K=E-06t2-0.011 3t+29.055. Meanwhile, un- der the condition, sound seedling index was not impacted a lot by excessive immer- sion. [Conclusion] This study has provided theoretical reference for guidance of sub- strate plot soaking method, cultivation and regulation, and breeding, as well as agri- cultural production. 展开更多
关键词 Substrate plot Saturation and expansion for absorption excessive water Regression equation
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Experiment and analysis of the formation,expansion and dissipation of gasbag in fine sediments based on pore water pressure survey
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作者 Shiyun Lei Xiujun Guo Haoru Tang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2022年第4期91-100,共10页
Deep-seated gas in seabed sediments migrates upwards from effect of external factors,which easily accumulates to form gasbags at interface of shallow coarse-fine sediments.Real-time monitoring of this process is impor... Deep-seated gas in seabed sediments migrates upwards from effect of external factors,which easily accumulates to form gasbags at interface of shallow coarse-fine sediments.Real-time monitoring of this process is important to predict disaster.However,there is still a lack of effective monitoring methods,so we attempt to apply multi-points pore water pressure monitoring technology when simulating forming and dissipation of gasbags in sediments through laboratory experiment.This study focuses on discussion of sensitivity of pore water pressure monitoring data,as well as typical changing characteristics and mechanisms of excess pore water pressure corresponding to crack generation,gasbag formation and gas release.It was found that the value of excess pore water pressure in sediments is negatively correlated with vertical distance between sensors and gas source,and the evolution of gasbag forming and dissipation has a good corresponding relationship with the change of excess pore water pressure.Gasbag formation process is divided into three stages:transverse crack development,longitudinal cavity expansion,and oblique crack development.Formation of gasbag begins with the transverse crack at the interface of coarse-fine sediments while excess pore water pressure attenuates rapidly and then drops,pressure remains almost unchanged when cavity expanses longitudinally,oblique crack appeared in final stage of gasbag evolution while excess pore water pressure accumulated and dissipated again.The variation curve of excess pore water pressure in gas release stage has saw-tooth fluctuation characteristics,and the value and time of pressure accumulation are also fluctuating,indicating the uncertainty and non-uniqueness of gas migration channels in sediments. 展开更多
关键词 pore water pressure monitoring technology excess pore water pressure gasbag cracks gas migration
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列车荷载作用下饱和路基翻浆冒泥特性研究
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作者 张家生 贾羽 +3 位作者 丁瑜 王晅 闫宏业 陈晓斌 《铁道工程学报》 EI CSCD 北大核心 2024年第7期11-17,33,共8页
研究目的:重载列车轴重的提高增大了路基不同深度处的动应力,由此引发的翻浆冒泥等病害日益严重。本文开展精细化模型试验,针对重载列车荷载作用下饱和粉质黏土路基的翻浆冒泥特性进行研究,分析循环荷载幅值及加载频率对试样轴向应变、... 研究目的:重载列车轴重的提高增大了路基不同深度处的动应力,由此引发的翻浆冒泥等病害日益严重。本文开展精细化模型试验,针对重载列车荷载作用下饱和粉质黏土路基的翻浆冒泥特性进行研究,分析循环荷载幅值及加载频率对试样轴向应变、超孔隙水压力及细颗粒迁移特性等性质的影响。研究结论:(1)循环荷载幅值对粉质黏土路基翻浆冒泥特性具有显著的影响,随着循环荷载幅值的增加,试样产生的轴向应变及超孔隙水压力增大,路基翻浆冒泥程度也不断增加;(2)加载频率对路基翻浆冒泥特性有一定影响,随着加载频率的增加,试样的最终轴向应变及超孔隙水压力均有所减小,试验结束后翻冒的泥浆质量减少;结合试验现象来看,加载频率的增加并不能加剧翻浆冒泥的程度,但能显著缩短翻浆冒泥发生的时间;(3)循环荷载作用下路基内部的超孔隙水压力梯度驱动路基土体细颗粒迁移,从而产生翻浆冒泥病害;(4)本研究成果可为重载铁路路基翻浆冒泥病害的整治提供参考。 展开更多
关键词 重载铁路 翻浆冒泥 轴向应变 超孔隙水压力 细颗粒迁移 超孔隙水压力梯度
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冲击荷载下含夹层饱和砂土孔压变化规律分析
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作者 金丹丹 鲁先东 +2 位作者 王炳辉 施展 张雷 《岩土力学》 EI CAS CSCD 北大核心 2024年第4期1081-1091,1120,共12页
砂土中夹层的性状会影响饱和砂土孔压发展,从而影响砂土层变形。为研究夹层位置、厚度和种类等不同夹层状态下砂土液化过程中的孔压变化规律,设计了冲击荷载作用下层状砂液化试验,建立了含夹层饱和砂土理论模型,并将试验结果与理论分析... 砂土中夹层的性状会影响饱和砂土孔压发展,从而影响砂土层变形。为研究夹层位置、厚度和种类等不同夹层状态下砂土液化过程中的孔压变化规律,设计了冲击荷载作用下层状砂液化试验,建立了含夹层饱和砂土理论模型,并将试验结果与理论分析进行对比。结果表明:含夹层饱和砂土的孔压发展呈现3个阶段,即快速上升、快速消散、缓慢消散阶段。高渗透性夹层高度越高,其下方土层孔压快速消散时长越短,越快趋于稳定值,但消散总时长无明显影响;低渗透性夹层高度或厚度的增大,均会使夹层上方孔压快速消散阶段速率加快,孔压消散稳定阶段延长,孔压消散总时长随之线性增长;同时,孔隙水会在低渗透性夹层下方形成水膜,夹层高度或厚度的增加均会使水膜持续时间增长,但水膜形态主要受夹层厚度影响。试验结果与理论分析较为一致,说明了试验的可靠性。 展开更多
关键词 层状砂土 冲击荷载 超孔隙水压力 夹层高度 夹层厚度 水膜
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基于能量的振冲碎石桩加密效果评价方法
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作者 周燕国 王春 +2 位作者 庄端阳 姚鹏飞 张东超 《岩土工程学报》 EI CAS CSCD 北大核心 2024年第S02期16-20,共5页
采用常规检测手段进行处理地基的工后质检存在时间滞后与空间局部的问题,不能及时反映处理地基的整体加固效果。提出了一种基于能量的碎石桩复合地基桩周土振动加密效果评价方法,为实现桩周土加密效果的准实时评价提供参考。首先,根据... 采用常规检测手段进行处理地基的工后质检存在时间滞后与空间局部的问题,不能及时反映处理地基的整体加固效果。提出了一种基于能量的碎石桩复合地基桩周土振动加密效果评价方法,为实现桩周土加密效果的准实时评价提供参考。首先,根据地基弹性波传播理论建立振冲施工过程中桩周土吸收波动能量的计算方法,通过不排水动三轴试验建立典型饱和粉砂土基于吸收能量的超静孔压模型,为进一步根据固结理论预测处理后复合地基桩周土密实度提供依据;其次,依托某工程水电站深厚坝基碎石桩处理工程实例,采用桩周土超静孔压峰值和处理后孔隙比两个关键物理量对方法进行了检验,发现与施工现场实测超静孔压和工后质检得到的孔隙比相比,方法的预测精度达到90%左右,说明基于能量的振冲碎石桩加密效果评价方法具有可行性。 展开更多
关键词 振冲碎石桩 振动能量 弹性波 留振加密 超静孔压
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Health Risk Assessment for Bromate (BrO<sub>3</sub><sup>–</sup>) Traces in Ozonated Indian Bottled Water
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作者 Ajay Kumar Sabyasachi Rout R.K. Singhal 《Journal of Environmental Protection》 2011年第5期571-580,共10页
For this study, bromide and bromate ions in various commercial brands of Indian bottled water samples were estimated using ion chromatography. The measured mean concentration of bromide and bromate ions in water sampl... For this study, bromide and bromate ions in various commercial brands of Indian bottled water samples were estimated using ion chromatography. The measured mean concentration of bromide and bromate ions in water samples was found to be 28.13 μg/L and 11.17 μg/L respectively. The average level of bromate in Indian bottled water was found to be slightly higher (~ 12%) than the acceptable limits (10 μg/L) recommended by USEPA (US Environmental Protection Agency). Though, kinetically, it is predicted that 62.5% (6.25 μg/L) of bromide in bottled water is needed to convert into bromate upon ozonation to exceed the minimum acceptable limits, but the average formation of bromate determined to be only 26.77% of the predicted concentration. Bromate concentration in bottled water showed a strong correlation with bromide suggesting that its formation in water is very much influenced and controlled by bromide content. The objective of the present study was to determine the BrO3–) content of commercially available different brands of bottled drinking water in India and to estimate the health risks to population due to ingestion. Results of estimated excess cancer risk and chemical toxicity risk to Indian population due to ingestion of bottled water were presented and discussed. 展开更多
关键词 BROMIDE BROMATE excess Cancer RISK Chemical Toxicity RISK BOTTLED water
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速度脉冲型地震动作用下局部可液化场地响应
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作者 赵密 曲恕宁 +1 位作者 申轶尧 钟紫蓝 《北京工业大学学报》 CAS CSCD 北大核心 2024年第9期1111-1121,共11页
为研究速度脉冲效应对可液化场地的影响,基于OpenSees平台建立有限元模型,对近断层速度脉冲型地震动与无速度脉冲地震动作用下局部可液化场地的竖向位移、加速度时程、土体剪应力-应变、超孔隙水压力比、循环应力比等土体的响应差异进... 为研究速度脉冲效应对可液化场地的影响,基于OpenSees平台建立有限元模型,对近断层速度脉冲型地震动与无速度脉冲地震动作用下局部可液化场地的竖向位移、加速度时程、土体剪应力-应变、超孔隙水压力比、循环应力比等土体的响应差异进行研究。数值计算结果表明:相同输入地震动幅值前提下,无脉冲地震动作用下可液化土体的竖向永久位移与位移发展持时平均值比速度脉冲型地震动作用分别大13%、19%;而速度脉冲型地震动作用下土体最大剪应变是无速度脉冲地震动的约5.4倍,最大剪应力约1.7倍;速度脉冲效应使土体的剪应力-剪应变滞回圈所围面积更大但滞回圈数量较少,且不同深度土体具有更大的循环应力比,从而促进土体发生液化;非液化密砂层放大地震动加速度幅值;液化松砂层对地震加速度时程进行了高频滤波,使地表加速度时程更为平滑且稀疏;速度脉冲效应作用下液化土层超孔隙水压力比整体较小,表明土体剪胀效应更加强烈。 展开更多
关键词 速度脉冲 液化场地 近断层地震 超孔隙水压力比 循环应力比 数值模拟
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关于超计划(定额)累进加价与用水权交易制度竞合的初步思考 被引量:1
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作者 郎劢贤 俞昊良 王海珍 《水利发展研究》 2024年第1期37-40,共4页
超计划(定额)累进加价制度已实行多年,对于强化节约用水管理发挥了重要作用。近年来,随着用水权改革的深入推进,两项制度在对公共供水管网内非居民用水户新增用水需求的管理上形成了竞合。文章基于对用水权权利范围边界的界定,提出了超... 超计划(定额)累进加价制度已实行多年,对于强化节约用水管理发挥了重要作用。近年来,随着用水权改革的深入推进,两项制度在对公共供水管网内非居民用水户新增用水需求的管理上形成了竞合。文章基于对用水权权利范围边界的界定,提出了超计划(定额)累进加价与用水权交易制度竞合的破解思路,并从持续深化用水权改革实践探索、深化理论研究方面提出了对策建议。 展开更多
关键词 超计划(定额)累进加价 用水权交易 制度竞合 用水权权利边界
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对ZYFM型油水分离器存在缺陷的分析和改进
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作者 李军 张辉 《武汉船舶职业技术学院学报》 2024年第3期92-97,共6页
分析了ZYFM型油水分离器的工作原理和自动控制原理,发现该型油水分离器设计上有缺陷,导致船员故意排放超标污油水。通过改进控制线路和换装气开式三通阀,消除了设计上的缺陷,彻底杜绝了船员恶意排放超标污油水的现象。该方法具有思路新... 分析了ZYFM型油水分离器的工作原理和自动控制原理,发现该型油水分离器设计上有缺陷,导致船员故意排放超标污油水。通过改进控制线路和换装气开式三通阀,消除了设计上的缺陷,彻底杜绝了船员恶意排放超标污油水的现象。该方法具有思路新、成本低、操作简单和就地取材的特点,实际应用效果显著,具有良好的市场推广前景。 展开更多
关键词 油水分离器 缺陷分析 超标排放 改进
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静钻根植桩施工环境效应现场试验研究 被引量:1
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作者 周佳锦 马俊杰 +2 位作者 俞建霖 龚晓南 张日红 《土木工程学报》 EI CSCD 北大核心 2024年第3期93-101,共9页
静钻根植桩采用先钻孔注浆后植桩的施工技术,可以解决传统预制桩施工过程引起的挤土效应问题。然而,静钻根植桩施工过程中钻孔和注浆过程会对周围土体产生一定扰动,目前没有相关研究。文章通过一组现场试验对静钻根植桩施工过程中的钻... 静钻根植桩采用先钻孔注浆后植桩的施工技术,可以解决传统预制桩施工过程引起的挤土效应问题。然而,静钻根植桩施工过程中钻孔和注浆过程会对周围土体产生一定扰动,目前没有相关研究。文章通过一组现场试验对静钻根植桩施工过程中的钻孔、注浆搅拌和植桩阶段对周围土体的扰动规律进行研究。静钻根植桩施工前在钻孔周围土体中埋设土压力传感器,孔隙水压力传感器和测斜管,分别测试静钻根植桩施工过程中周围土体中水平土压力,超静孔隙水压力和深层土体水平位移的变化规律。研究结果表明:静钻根植桩施工过程会对周围土体造成一定扰动,而施工完成后周围土体中的水平土压力、超静孔隙水压力和深层土体水平位移迅速恢复;当水平距离达到4D(D为钻孔直径)时,静钻根植桩施工过程基本不会对土体产生影响;试验结果可以为静钻根植桩在地铁周围等施工位移控制敏感区域的应用提供理论依据。 展开更多
关键词 静钻根植桩 环境效应 水平土压力 超静孔隙水压力 土体水平位移
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饱和砂土液化特性的振动台试验研究 被引量:1
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作者 赵轩 马淑芝 +1 位作者 马硕 文生奡 《地震工程学报》 CSCD 北大核心 2024年第2期376-387,共12页
基于地震模拟振动台试验,配制3组不同平均粒径和3组不同细粒含量的6个砂土模型,通过埋置于砂土内部的传感器监测模型内部不同位置的超孔隙水压力等指标,分析砂土模型内部的超孔隙水压力时程曲线及孔压比时程曲线,归纳出地震波加载峰值... 基于地震模拟振动台试验,配制3组不同平均粒径和3组不同细粒含量的6个砂土模型,通过埋置于砂土内部的传感器监测模型内部不同位置的超孔隙水压力等指标,分析砂土模型内部的超孔隙水压力时程曲线及孔压比时程曲线,归纳出地震波加载峰值、砂土平均粒径、细粒含量及埋置深度等因素对饱和砂土液化特性的影响规律。试验结果表明:随着地震波加载峰值的增大,砂土模型液化程度逐渐增大,液化势逐渐增大,抗液化强度逐渐减小;随着砂土埋置深度的增加,砂土细粒含量的增加,砂土平均粒径的增加,砂土模型液化程度逐渐减小,液化势逐渐减小,其抗液化强度逐渐增大。同时,试验结果还表明,砂土液化各影响因素对砂土液化的影响程度依次为地震波强度>砂土埋置深度>砂土平均粒径、细粒含量。试验结果可为后续数值模拟的参数选取提供支持,为研究其他因素对砂土液化的影响提供参考。 展开更多
关键词 砂土液化 影响因素 振动台 超孔隙水压力 孔压比
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软土地层盾构地中对接法孔压扰动规律研究
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作者 王彪 陈星欣 +2 位作者 尹清锋 郭力群 何明高 《岩土力学》 EI CAS CSCD 北大核心 2024年第S01期535-549,共15页
在软土地层中应用盾构地中对接法能大大缩短长隧道施工周期,但先、后行盾构施工在盾构对接段产生的超静孔隙水压力会影响土体应力状态和地层稳定性。建立软土地层盾构地中对接法的流固耦合模型,在时间方面,分析了盾构地中对接横断面上... 在软土地层中应用盾构地中对接法能大大缩短长隧道施工周期,但先、后行盾构施工在盾构对接段产生的超静孔隙水压力会影响土体应力状态和地层稳定性。建立软土地层盾构地中对接法的流固耦合模型,在时间方面,分析了盾构地中对接横断面上不同距离的超静孔隙水压力时间分布;在空间方面,分析了先、后行盾构施工引起的超静孔隙水压力纵向分布,以及盾构对接施工过程引起的超静孔隙水压力横断面分布。另外,分析了盾构地中对接施工对孔隙水压力的扰动规律,并进行施工参数分析。结果表明:完成盾构对接时,盾构施工对拱顶扰动范围最大,侧边次之,底部最小;后行盾构施工对开挖面前方的超静孔隙水压力影响范围是先行盾构施工的1.5倍,其值大约为3.4倍的隧道直径;当分层土体的渗透性差异过大时,会出现超静孔隙水压力突变的情况;在盾构地中对接施工过程中,先行盾构施工阶段产生的扰动影响要远大于后行盾构,至对接位置时,先行盾构对拱顶产生的孔压扰动指标是后行盾构的2倍左右;对接点处未进行注浆加固时,建议先、后行盾构在距对接点2D(D为隧道外径)前,将掌子面支护力减小至0.8倍标准掌子面支护力,或在先行盾构到达对接点前进行超前注浆加固,以减小盾构对接施工过程的扰动影响。 展开更多
关键词 软土地层 盾构对接 超静孔隙水压力 扰动度
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双洞隧道地铁运行引起的软土地基振动及孔压研究
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作者 丁峰 程扬 +2 位作者 钱春宇 宋春雨 陈龙珠 《土木工程与管理学报》 2024年第5期71-77,共7页
建立双洞隧道的三维有限差分模型,通过车轨耦合计算得到地铁运行中隔振器的力时程,以集中力的形式施加到地铁轨道对应的节点上,分析探讨了软土地基中振动加速度和超静孔隙水压力的变化规律及影响范围等。结果表明:左侧隧道和右侧隧道振... 建立双洞隧道的三维有限差分模型,通过车轨耦合计算得到地铁运行中隔振器的力时程,以集中力的形式施加到地铁轨道对应的节点上,分析探讨了软土地基中振动加速度和超静孔隙水压力的变化规律及影响范围等。结果表明:左侧隧道和右侧隧道振动及孔隙水压力的变化基本一致,在地铁的一次相向运行过程中,软土地基的地表竖向振动加速度在两隧道中心处出现最大值,在距隧道中心轴约25 m处存在地表振动加速度放大现象,在距隧道中心轴150 m外,地表加速度峰峰值衰减至2 gal以下。软土地基中的超静孔隙水压力随着远离隧道而快速减小,在距隧道中心轴80 m外,超静孔隙水压力便衰减至100 Pa以下。白天地铁运行过程中,超静孔隙水压力出现较平稳的振荡,晚间地铁停运后,超静孔隙水压力出现一定程度下降,且随着地铁的反复运行下降幅度减小。 展开更多
关键词 双洞隧道 软土地基 数值模拟 振动响应 超静孔隙水压力
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软黏土地层盾构隧道底部注浆抬升量计算方法
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作者 孟凡衍 贾琪 +2 位作者 陈仁朋 陈曈 程红战 《岩土工程学报》 EI CAS CSCD 北大核心 2024年第11期2401-2409,共9页
下部地层注浆是盾构隧道过大沉降的常用治理措施。结构性软黏土地层中注浆引起的超孔压在注浆后持续消散,导致隧道抬升后因地层固结而发生沉降,进而降低隧道抬升效率。为预测下方地层注浆引起的盾构隧道纵向变形,提出了考虑土体结构性... 下部地层注浆是盾构隧道过大沉降的常用治理措施。结构性软黏土地层中注浆引起的超孔压在注浆后持续消散,导致隧道抬升后因地层固结而发生沉降,进而降低隧道抬升效率。为预测下方地层注浆引起的盾构隧道纵向变形,提出了考虑土体结构性的盾构隧道底部注浆抬升量—沉降量两阶段计算方法。应用于宁波地铁2号线注浆抬升案例,隧道抬升效率计算值约51%,与同为软黏土地层的上海地铁2号线某区间盾构隧道实测抬升效率非常接近。此外,针对注浆参数、地层参数与隧道参数开展了参数分析,结果表明:隧道最终抬升量及抬升效率与土体基床系数、注浆体积呈正相关,与地层屈服应力成负相关;随埋深比增大,注浆区域隧道最终抬升量减小,而抬升效率变化甚微。计算方法可以为软黏土地层运营盾构隧道注浆抬升设计提供理论支撑。 展开更多
关键词 结构性黏土 注浆 隧道抬升 超孔压消散 固结沉降
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