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Analysis of diffusion-adsorption equivalency of landfill liner systems for organic contaminants

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Journal of Environmental Sciences 2009年第4期21卷 552-560页

作者： XIE Haijian, CHEN Yunmin, KE Han, TANG Xiaowu, CHEN Renpeng MOE key laboratory of soft soils and geoenvironmental engineering, Zhejiang University, Hangzhou 310027, China. [a]MOE key laboratory of soft soils and geoenvironmental engineering Zhejiang University Hangzhou 310027 China

The equivalence between multilayered barriers regarding diffusion and adsorption was studied. The bottom boundary of the liner system is defined by assuming concentration continuous and flux continuous conditions of the contaminant between the bottom liner layer and the underlying soil. Five different liner systems were compared in terms of solute breakthrough time. The results of the analysis showed that breakthrough time of the hydrophobic organic compounds for a 2-meter-thick compacted clay liner （CCL） could be 3-4 orders of magnitude is greater than the breakthrough time for a geosynthetic clay liner （GCL） composite liner. The GM/GCL and GM/CCL composite liner systems provide a better diffusion barrier for the hydrophilic organic compounds than that for the hydrophobic compounds due to their different Henry＇s coefficient. The calculated breakthrough times of the organic contaminants for the Chinese standard liner systems were found to be generally greater than those for the GCL alternatives, for the specific conditions examined. If the distribution coefficient increases to 2.8 for the hydrophobic compounds or 1.0 for the hydrophilic compounds, the thickness of the attenuation layer needed to achieve the same breakthrough time as the standard liner systems can be reduced by a factor of about 1.9-2.4. As far as diffusive and adsorption contaminant transport are concerned, GM or GCL is less effective than CCL.

关键词： liner system equivalency organic contaminant landfill diffusion adsorption

Analytical solution and semi-analytical solution for anisotropic functionally graded beam subject to arbitrary loading

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Science China(Physics,Mechanics & Astronomy) 2009年第8期52卷 1244-1256页

作者： HUANG DeJin1,2,DING HaoJiang1 & CHEN WeiQiu3 1 key laboratory of soft soils and geoenvironmental engineering,ministry of education,Zhejiang University,Hangzhou 310027,China 2 Faculty of engineering,Ningbo University,Ningbo 315211,China 3 Department of engineering Mechanics,Zhejiang University,Hangzhou 310027,China key laboratory of soft soils and geoenvironmental engineering Ministry of Education Zhejiang University Hangzhou 310027 China Faculty of engineering Ningbo University Ningbo 315211 China Department of engineering Mechanics Zhejiang University Hangzhou 310027 China

Analytical and semi-analytical solutions are presented for anisotropic functionally graded beams subject to an arbitrary load,which can be expanded in terms of sinusoidal *** plane stress problems,the stress function is assumed to consist of two parts,one being a product of a trigonometric function of the longitudinal coordinate(x) and an undetermined function of the thickness coordinate(y),and the other a linear polynomial of x with unknown coefficients depending on *** governing equations satisfied by these y-dependent functions are *** expressions for stresses,resultant forces and displacements are then deduced,with integral constants determinable from the boundary *** the analytical solution is derived for the beam with material coefficients varying exponentially or in a power law along the thickness,the semi-analytical solution is sought by making use of the sub-layer approximation for the beam with an arbitrary variation of material parameters along the *** present analysis is applicable to beams with various boundary conditions at the two *** numerical examples are presented for validation of the theory and illustration of the effects of certain parameters.

关键词： anisotropic material functionally graded arbitrary loading stress function analytical solution semi-analytical solution

Guided wave propagation in multilayered piezoelectric structures

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Science China(Physics,Mechanics & Astronomy) 2009年第7期52卷 1094-1104页

作者： GUO YongQiang1, CHEN WeiQiu2,3 & ZHANG YongLiang4 1 key laboratory of Mechanics on Disaster and Environment in Western China, ministry of education, and School of Civil engineering and Mechanics, Lanzhou University, Lanzhou 730000, China 2.key laboratory of soft soils and geoenvironmental engineering, ministry of education, and Department of Civil engineering, Zhejiang University, Hangzhou 310058, China 3 Department of engineering Mechanics, Zhejiang University, Hangzhou 310027, China 4 School of Civil engineering, Lanzhou Jiaotong University, Lanzhou 730070, China key laboratory of Mechanics on Disaster and Environment in Western China Ministry of Education and School of Civil Engineering and Mechanics Lanzhou University Lanzhou 730000 China key laboratory of soft soils and geoenvironmental engineering Ministry of Education and Department of Civil Engineering Zhejiang University Hangzhou 310058 China Department of engineering Mechanics Zhejiang University Hangzhou 310027 China School of Civil engineering Lanzhou Jiaotong University Lanzhou 730070 China

A general formulation of the method of the reverberation-ray matrix (MRRM) based on the state space formalism and plane wave expansion technique is presented for the analysis of guided waves in multilayered piezoelectric structures. Each layer of the structure is made of an arbitrarily anisotropic piezoelectric material. Since the state equation of each layer is derived from the three-dimensional theory of linear piezoelectricity, all wave modes are included in the formulation. Within the framework of the MRRM, the phase relation is properly established by excluding exponentially growing functions, while the scattering relation is also appropriately set up by avoiding matrix inversion operation. Consequently, the present MRRM is unconditionally numerically stable and free from computational limitations to the total number of layers, the thickness of individual layers, and the frequency range. Numerical examples are given to illustrate the good performance of the proposed formulation for the analysis of the dispersion characteristic of waves in layered piezoelectric structures.

关键词： multilayered piezoelectric structures the method of reverberation-ray matrix guided waves dispersion characteristic

Shear wave velocity-based liquefaction evaluation in the great Wenchuan earthquake: a preliminary case study

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Earthquake engineering and engineering Vibration 2009年第2期8卷 231-239页

作者： Zhou Yanguo,Chen Yunmin and Ling Daosheng MOE key laboratory of soft soils and geoenvironmental engineering,Institute of Geotechnical engineering,Zhejiang University,Hangzhou 310058,China Assistant Professor Professor MOE key laboratory of soft soils and geoenvironmental engineering Zhejiang University Hangzhou 310058 China MOE key laboratory of soft soils and geoenvironmental engineering Zhejiang University 388 Yuhangtang Road Hangzhou 310058 China

The great Wenchuan earthquake （Ms= 8.0） in 2008 caused severe damage in the western part of the Chengdu Plain. Soil liquefaction was one of the major causes of damage in the plain areas, and proper evaluation of liquefaction potential is important in the definition of the seismic hazard facing a given region and post-earthquake reconstruction. In this paper, a simplified procedure is proposed for liquefaction assessment of sandy deposits using shear wave velocity （V）, and soil liquefaction from the Banqiao School site was preliminarily investigated after the earthquake. Boreholes were made at the site and shear wave velocities were measured both by SASW and down-hole methods. Based on the in-situ soil information and V profiles, the liquefaction potential of this site was evaluated. The results are reasonably consistent with the actual field behavior observed after the earthquake, indicating that the proposed procedure is effective. The possible effects of gravel and fines contents on liquefaction of sandy soils were also briefly discussed.

关键词： liquefaction Wenchuan earthquake shear wave velocity spectral analysis of surface waves (SASW) hazarddefinition

An analytical solution to contaminant transport through composite liners with geomembrane defects

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中国科学：技术科学英文版 2010年第5期53卷 1424-1433页

作者： XIE HaiJian1,2,CHEN YunMin1 & LOU ZhangHua1,2 1MOE key laboratory of soft soils and geoenvironmental engineering,Zhejiang University,Hangzhou 310058,China 2Institute of Hydrology and Water Resources engineering,Zhejiang University,Hangzhou 310058,China 1. MOE key laboratory of soft soils and geoenvironmental engineering Zhejiang University Hangzhou 310058 China2. Institute of Hydrology and Water Resources Engineering Zhejiang University Hangzhou 310058 China

To investigate the performance of landfill composite liner system,a one-dimensional model was developed for solute transport through composite liners containing geomembrane *** analytical solution to the model was obtained by the method of Laplace *** results obtained by the presented solution agree well with those obtained by the numerical *** show that leachate head and construction quality of geomembrane(GM) have significant influences on the performance of the composite liners for heavy metal *** breakthrough time of lead decreases from 50 a to 19 a when the leachate head increases from 0.3 m to 10 *** is also indicated that the contaminant mass flux of volatile organic compounds(VOCs) induced by leakage can not be neglected in case of poor construction quality of the landfill barrier *** is shown that diffusion coefficient and partition coefficient of GM have great influences on solute transport through composite liners for *** breakthrough time of heavy metal ions will be greatly overestimated if the effects of diffusion and adsorption of clay and geosynthetic clay liner(GCL) are *** composite liner consisting of a geomembrane and a GCL provides a poor barrier for *** presented analytical solution is relatively simple to apply and can be used for preliminary design of composite liners,evaluating experimental results,and verifying more complex numerical models.

关键词： defect composite liner contaminant transport analytical solution leachate head landfill groundwater contamination

Steady-state response of a saturated half-space with an overlying dry layer subjected to a moving load

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2012年第1期13卷 33-43页

作者： An-feng HU Bo SUN Kang-he XIE MOE key laboratory of soft soils and geoenvironmental engineering Zhejiang University Hangzhou 310058 China

In this paper,the steady-state response of a saturated half-space with an overlying dry layer subjected to a moving rectangular load is *** governing partial differential equations are solved using the Fourier *** solutions in time-space domain are expressed in terms of infinite Fourier type integrals,which can be evaluated only by numerical *** results show that the influence of a drained or undrained interface on the response is related to the permeability of the underlying saturated ***,the effect due to the upper dry layer is associated with the thickness of the layer.

关键词： Steady-state response Moving load Saturated half-space Overlying dry layer Fourier transform Drained orundrained interface

折线形填埋场排水系统最大浸润线水位深度的计算

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土木工程学报 2011年第4期44卷 105-111页

作者：柯瀚陈云敏沈磊浙江大学软土和环境土工国家教育部重点实验室浙江杭州310027

在实际的填埋场设计中,存在着排水系统由两段或多段不同坡度的折线段组成的情况,目前对折线形排水系统最大水位深度的准确估算只适用于非常有限的几种情况。依据扩展的Dupuit假设,导出折线形排水系统在自由出流边界条件下的浸润线求解... 详细信息

在实际的填埋场设计中,存在着排水系统由两段或多段不同坡度的折线段组成的情况,目前对折线形排水系统最大水位深度的准确估算只适用于非常有限的几种情况。依据扩展的Dupuit假设,导出折线形排水系统在自由出流边界条件下的浸润线求解方法。通过案例分析及与Giroud等的计算结果比较,证明所提出的方法是合理和准确的。在此基础上,进行多参数分析。在一般情况下,下坡的最大液面高度取决于总长度、下游坡度及入渗强度。在计算上坡最大水头高度的时候,应该考虑由于下坡积水引起的上下坡交界处的水位。复合排水材料对减少最大水位深度有着重要的意义。

关键词：填埋场复合排水系统渗滤液最大水位深度

MODELING OF MULTILAYERED ACOUSTIC WAVE DEVICES WITH THE METHOD OF REVERBERATION-RAY MATRIX

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MODELING OF MULTILAYERED ACOUSTIC WAVE DEVICES WITH THE METH...

第三届全国压电和声波理论及器件技术研讨会

作者： Yong-qiang GUO key laboratory of Mechanics on Disaster and Environment in Western China,ministry of education, and School of Civil engineering and Mechanics,Lanzhou University,Lanzhou 730000,China Wei-qiu CHEN key laboratory of soft soils and geoenvironmental engineering,ministry of education, and Department of Civil engineering,Zhejiang University,Hangzhou 310027,China

The method of reverberation-ray matrix(MRRM) are modified and extended to the analysis of wave propagation in multilayered acoustic wave devices based on three-dimensional linear *** the plane wave solution assumption,state equations are established whose solutions are expressed with unknown wave *** the framework of MRRM,the phase and scattering relations are properly set up to determine the unknowns without involving exponentially growing functions and matrix inversion operations in an easy and uniform *** the present MRRM is unconditionally stable and free from limitations to the frequency,the thickness of individual layers and the total number of *** surface waves,the interface waves and the bulk waves are all included in the formulation. Therefore,the present formulation applies to SAW devices as well as BAW *** examples are given to illustrate the well performance of the proposed formulation of MRRM for the analysis of free waves in multilayered acoustic wave devices.

关键词： Multilayered piezoelectric structures acoustic wave devices wave propagation method of reverberation-ray matrix

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基于模型试验的高铁路基动力累积变形研究

土木工程学报 2011年第6期44卷 112-119页

作者：边学成蒋红光申文明陈云敏浙江大学软弱土与环境土工教育部重点实验室浙江杭州310058 浙江大学岩土工程研究所浙江杭州310058

高速列车运行中的轮轴往复动荷载引起铁路线下结构产生累积变形,导致轨道平顺性变差,影响列车运行的舒适性和安全性,列车交通荷载引起的路基累积变形是高速铁路线路设计和运营维护中必须考虑的一个重要问题。基于残余应变模型建立了列... 详细信息

高速列车运行中的轮轴往复动荷载引起铁路线下结构产生累积变形,导致轨道平顺性变差,影响列车运行的舒适性和安全性,列车交通荷载引起的路基累积变形是高速铁路线路设计和运营维护中必须考虑的一个重要问题。基于残余应变模型建立了列车轮轴循环动荷载作用下路基填料和下卧层地基土体的累积变形计算方法;通过物理模型试验验证了该模型和计算方法的合理性,并确定了相应的关键参数取值方法,实验结果表明该模型参数具有较好的一致性。最后,通过将计算模型应用到具体的高速铁路线路动力沉降分析中,揭示了路基基床底层和地基累积变形的发展规律,分析了列车轴重和循环次数等主要控制因素的影响作用。

关键词：循环荷载路基填料地基土累积变形高速铁路