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A Laboratory Modeling of the Velocity Field in the Convective Boundary Layer with the Particle Image Velocimetry Technique 被引量:5
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作者 李萍阳 蒋维楣 +1 位作者 孙鉴泞 袁仁民 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2003年第4期631-637,共7页
Based on the research of the convective boundary layer (CBL) temperature field in a convective tank, this paper studies the characteristics of the CBL velocity field in the convective tank. Aluminium powder (400 order... Based on the research of the convective boundary layer (CBL) temperature field in a convective tank, this paper studies the characteristics of the CBL velocity field in the convective tank. Aluminium powder (400 orders) is used as a tracer particle in the application of the particle image velocimetry (PIV) technique. The experiment demonstrates: the velocity distribution in the mixed layer clearly possesses the characteristics of CBL thermals; the velocity distribution in the top zone of the mixed layer shows entrainment layer characteristics; the vertical distribution of turbulent characteristic variables is reasonable, which is similar to field observations and other tank results; the error analysis demonstrates the validity of aluminium powder, which implies the reliability of the results. 展开更多
关键词 velocity field convective boundary layer (CBL) convective water tank PIV technique
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False anomaly recognition with horizontal differential field lines method in high-density electrical technique and its application in Xinlei Quarry,Jiuquan 被引量:2
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作者 LIU Lijia ZHU Shi +2 位作者 CAO Xiaoyue BEN Fang YIN Changchun 《Global Geology》 2015年第2期140-144,共5页
As an important geophysical tool,high density electrical technique infers the underground geological structures by processing and inverting the apparent resistivity data.Currently,the false anomalies have been frequen... As an important geophysical tool,high density electrical technique infers the underground geological structures by processing and inverting the apparent resistivity data.Currently,the false anomalies have been frequently occurred in the graph of apparent resistivity pseudo-section or inverted geoelectrical section obtained from high-density electrical technique,and are difficult to remove.In this study,the authors explain the mechanism of the false anomalies and put forward the horizontal differential field method to identify the false anomalies.Based on the analysis of modeling results,this method is applied in the surveying data in Xinlei Quarry of Jiuquan,and the results confirm the effectiveness of the horizontal differential field method. 展开更多
关键词 horizontal differential field method high density electrical technique apparent resistivity false anomaly
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A Sound Field Separation and Reconstruction Technique Based on Reciprocity Theorem and Fourier Transform 被引量:1
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作者 Xiao-Lei Li Ning Wang +1 位作者 Da-Zhi Gao Qi Li 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第11期42-45,共4页
We show a method to separate the sound field radiated by a signal source from the sound field radiated by noise sources and to reconstruct the sound field radiated by the signal source. The proposed method is based on... We show a method to separate the sound field radiated by a signal source from the sound field radiated by noise sources and to reconstruct the sound field radiated by the signal source. The proposed method is based on reciprocity theorem and the Fourier transform. Both the sound field and its gradient on a measurement surface are needed in the method. Evanescent waves are considered in the method, which ensures a high resolution reconstruction in the near field region of the signal source when evanescent waves can be measured. A simulation is given to verify the method and the influence of measurement noise on the method is discussed. 展开更多
关键词 A Sound field Separation and Reconstruction technique Based on Reciprocity Theorem and Fourier Transform
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THEORY AND APPLICATION OF FIELD PERTURBATION TO ELECTRICAL IMPEDANCE TECHNIQUE FOR MEDICINE
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作者 万明习 程敬之 《Journal of Electronics(China)》 1991年第4期324-333,共10页
A new approach called field perturbation theory is presented to analyze the electricalimpedance technique for medicine.The formula of constant voltage and constant current fieldperturbation,modified G-L formula and th... A new approach called field perturbation theory is presented to analyze the electricalimpedance technique for medicine.The formula of constant voltage and constant current fieldperturbation,modified G-L formula and the formula of electrical field perturbation evoked bysound field are derived.The application results of the theory in electroglottography are alsointroduced. 展开更多
关键词 ELECTRICAL IMPEDANCE technique for MEDICINE ELECTRICAL field PERTURBATION ELECTROGLOTTOGRAPHY
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A Smart Substation Field Secondary Device Testing Technique Based on Recurrence Principle
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作者 Kanjun Zhang Lei Chen +5 位作者 Yongjun Xia Yang Lei Xin Shu Hengxuan Li Ting Wang Zhenan Du 《Journal of Power and Energy Engineering》 2014年第4期244-251,共8页
According to the demand of substation secondary device dynamic performance testing, a smart substation field testing technique based on recurrence principle is proposed in the paper, and the characteristics of smart s... According to the demand of substation secondary device dynamic performance testing, a smart substation field testing technique based on recurrence principle is proposed in the paper, and the characteristics of smart substation secondary device digitization and information sharing are used by the technique. The principle of testing technique is as follow: the digital simulation model is constructed on the basis of the substation’s actual construction, then the simulating data highly similar to substation’s actual electric quantity transient process is generated, at last, the substation digital secondary device can be tested by using data “recurrence” technique. The testing technique is verified and applied by constructing testing system, the application results show that the technique can effectively perform field test on the dynamic performance of digital secondary device, and the technique has good engineering implementation and application value. 展开更多
关键词 Smart Substation SECONDARY DEVICE Dynamic Performance Data RECURRENCE field TESTING technique
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Research on Techniques for Rolling Exploration and Development and Application to Dongying Oilfield
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作者 Du Xiangyue and Sun Longde 《China Oil & Gas》 CAS 1995年第1期35-39,共5页
ResearchonTechniquesforRollingExplorationandDevelopmentandApplicationtoDongyingOilfieldDuXiangyueandSunLongd... ResearchonTechniquesforRollingExplorationandDevelopmentandApplicationtoDongyingOilfieldDuXiangyueandSunLongdeKeywords:Oilfiel... 展开更多
关键词 OIL field ROLLING EXPLORATION and DEVELOPMENT technique RESERVE
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Dewatering Techniques for Gas Recovery in Sichuan Gas Fields
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作者 Xu Kefang(Director,Development & Production Department,Sichuan Petroleum Administration) 《China Oil & Gas》 CAS 1996年第2期97-98,共2页
DewateringTechniquesforGasRecoveryinSichuanGasFields¥XuKefang(Director,Development&ProductionDepartment,Sich... DewateringTechniquesforGasRecoveryinSichuanGasFields¥XuKefang(Director,Development&ProductionDepartment,SichuanPetroleumAdmin... 展开更多
关键词 GAS field GAS RECOVERY DEWATERING technique
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Fabrication of Grain-oriented (Bi,Pb)_2Sr_2Ca_2Cu_3O_x Superconducting Tapes Using Magnetic Field and Vibration Technique
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作者 Yanwei MA and Xianjin WANG (Dept. of Metal Forming, University of Science and Technology Beijing, Beijing 100083, China)Zutang WANG (Tsinghua University, Beijing 100084, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1998年第1期86-88,共3页
Highly textured (Bi,Pb)2Sr2Ca2Cu3Ox superconducting tapes have been fabricated by means of magnetic-field and vibration technique. This method is an effective way of improving the degree of grain alignment and density... Highly textured (Bi,Pb)2Sr2Ca2Cu3Ox superconducting tapes have been fabricated by means of magnetic-field and vibration technique. This method is an effective way of improving the degree of grain alignment and density of oxide core in tapes after heat treatment and pressing cycles.Jc of above 20% was increased than that without treatment. 展开更多
关键词 Bi Pb PB Sr Fabrication of Grain-oriented x Superconducting Tapes Using Magnetic field and Vibration technique Ca Cu
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Field Identification and Prevention and Control Techniques of Citrus Huanglongbing of Orah Mandarin
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作者 Qichun HUANG Nina WANG +7 位作者 Huihong LIAO Wenshen LIANG Jimin LIU Hongming HUANG Fuping LIU Zelin QIN Zhikang ZENG 《Plant Diseases and Pests》 CAS 2022年第3期11-14,共4页
In order to promote the development of Orah mandarin industry in Guangxi and reduce the harm of citrus huanglongbing to Orah mandarin,the pathogen,characteristics,occurrence regularity and field symptoms of citrus hua... In order to promote the development of Orah mandarin industry in Guangxi and reduce the harm of citrus huanglongbing to Orah mandarin,the pathogen,characteristics,occurrence regularity and field symptoms of citrus huanglongbing were summarized,and scientific prevention and control measures were put forward,such as strict implementation of quarantine system,cultivation and use of disease-free seedlings,strengthening field management,timely control of psyllid,timely removal of diseased trees,etc. 展开更多
关键词 Citrus huanglongbing Orah mandarin field symptom Prevention and control technique
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Effective Field Theory Techniques Applied to the Properties of the Axion
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作者 凌锐 平加伦 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第5期35-38,共4页
We utilize the effective field theory approach to study the properties of the axion. In particular, with s as well as u and d quarks regarded to be relatively light we derive a formula for the mass of the axion; a rou... We utilize the effective field theory approach to study the properties of the axion. In particular, with s as well as u and d quarks regarded to be relatively light we derive a formula for the mass of the axion; a rough estimate of the rate for its dominant decay mode at low energy is also carried out. 展开更多
关键词 Effective field Theory techniques Applied to the Properties of the Axion
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Calculation of the contribution of single-zone production by ultraviolet spectrum technique:A case study in well QHD32-6-3 field
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作者 徐耀辉 陈丹 +2 位作者 向廷生 文志刚 林青 《Chinese Journal Of Geochemistry》 EI CAS 2007年第1期80-83,共4页
Based on the established mathematic model and graphic interpretation, a new method, which is used to calculate the contribution of single-zone production in a commingled producing well by the ultraviolet spectrum tech... Based on the established mathematic model and graphic interpretation, a new method, which is used to calculate the contribution of single-zone production in a commingled producing well by the ultraviolet spectrum technique, has been established. The standard plate was drawn using the extinction coefficient E of sample oils formulated artificially as y-axis and the wavelength as x-axis. The curve resulting from the UV analysis of sample oils in the commingled well was inserted into the standard plate and compared. The proportion of each single zone in the commingled producing well was identical with the proportion of the curve which is closest to the curve of sample oils formulated artificially. In the well QHD32-6-3 field, taking well A22 for example and using this method, the production contribution of a single zone was calculated. The result showed that the Nm4 zone is a major "contributor", the proportion of the Nm4 zone is 70%, and that of the Nm1 zone is 30%. The ultraviolet spectrum technique provided a new reservoir geochemical technique of monitoring production contribution, especially for biodegraded heavy oil, but it has some limitation, just depending on the GC fingerprint technique. 展开更多
关键词 紫外光谱技术 单区生产 计算 合采井 重油
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Regulation technique in soil moisture at paddy field
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作者 SITU Song 《Chinese Rice Research Newsletter》 1996年第2期8-9,共2页
Early cultivator Zhongzao 1(indica)and late rice cultivar Xiushui 2(japonica)were used for field experiments.Seedlings were transplantedon May 13 and Jun 28 respectively in spaced at5 cm between row and 4 cm within ro... Early cultivator Zhongzao 1(indica)and late rice cultivar Xiushui 2(japonica)were used for field experiments.Seedlings were transplantedon May 13 and Jun 28 respectively in spaced at5 cm between row and 4 cm within row with 4plants per hill.Treatments were started at thetime when the young plants had 80~ available 展开更多
关键词 Regulation technique in soil moisture at paddy field
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Notable effects on comprehensive techniques of man-made biosphere in rice fields
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作者 Feng Yilen,CNRRI 《Chinese Rice Research Newsletter》 1996年第4期12-12,共1页
Studied by Mr. LIU Zhongzhu, ex Chairman of Fujian Academy of Agri Sciences, a combined technique of man—made biosphere in rice fields deserves notice. The research indicated that using man—made biosphere in rice fi... Studied by Mr. LIU Zhongzhu, ex Chairman of Fujian Academy of Agri Sciences, a combined technique of man—made biosphere in rice fields deserves notice. The research indicated that using man—made biosphere in rice fields can enrich soil, reduce the infects of diseases, insects and weeds, economize the use of pesticide and herbicide, decrease green house effect, and improve atmosphere. As tested, the yield for rice is usually 10500—12000 kg/ha, for fish is usually 2250—3250 kg/ha. Again, about 50%—60% fertilizer and 30%—50% pesticide can be saved. The net income increased $ 1,080—1,800 per ha. 展开更多
关键词 Notable effects on comprehensive techniques of man-made biosphere in rice fields
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CALCULATION AND EXPERIMENTAL INVESTIGATION OF ELECTRIC FIELDS INDUCED BY ELECTRODES IN ELECTROSTATIC CHARGED POWDER SPRAYING TECHNIQUE
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作者 Wang Ze Luo Tiqian(Jiangsu University of Science and Technology 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 1995年第1期26-29,共17页
Electric fields induced by ring and pin electrodes in electrostatic charged powder sprayingtechnique are analysed. The fundamental formulae to deseribe these fields have been built up. Theseformulae could be used to d... Electric fields induced by ring and pin electrodes in electrostatic charged powder sprayingtechnique are analysed. The fundamental formulae to deseribe these fields have been built up. Theseformulae could be used to design electrostatic charged podwer spraying system. The chargingeffectiveness of ring and pin electrode is experimentally investigated and compared each other. Theperformance of ring electrode is better than that of pin electrode. 展开更多
关键词 Electrostatic charging powder spraying technique Electric field ElectrodeCharging effectiveness
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Femtosecond electron pulse compression by using the time focusing technique in ultrafast electron diffraction 被引量:3
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作者 温文龙 雷晓红 +7 位作者 胡昕 徐向晏 王俊锋 曹希斌 刘虎林 王超 党利宏 田进寿 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第11期228-232,共5页
We present a new model of an electron gun for generating subrelativistic femtosecond (fs) electron pulses. The basic idea is to utilize a dc acceleration stage combined with a time focusing region, the time focusing... We present a new model of an electron gun for generating subrelativistic femtosecond (fs) electron pulses. The basic idea is to utilize a dc acceleration stage combined with a time focusing region, the time focusing electrode generates an electron energy chirp for bunching at the target. Without considering the space charge effects, simulations of the electron gun were carried out under the conditions of different dc voltages and various slopes of the voltage added on the time focusing electrode. Tracing and simulating large numbers of photoelectrons through Monte-Carlo and finite difference methods, the electron pulses with 1 ps can be compressed to 55 fs, which will allow significant advances in the field of ultrafast diagnosis. 展开更多
关键词 time focusing technique temporal pulse compressing time-dependent electric field Monte Carlo method
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Reconstruction of the Unsteady Supersonic Flow around a Spike Using the Colored Background Oriented Schlieren Technique 被引量:5
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作者 Friedrich Leopold Masanori Ota +1 位作者 Daniel Klatt Kazuo Maeno 《Journal of Flow Control, Measurement & Visualization》 2013年第2期69-76,共8页
In this paper, the improved Background Oriented Schlieren technique called CBOS (Colored Background Oriented Schlieren) is described and used to reconstruct the density fields of three-dimensional flows. The Backgroun... In this paper, the improved Background Oriented Schlieren technique called CBOS (Colored Background Oriented Schlieren) is described and used to reconstruct the density fields of three-dimensional flows. The Background Oriented Schlieren technique (BOS) allows the measurement of the light deflection caused by density gradients in a compressible flow. For this purpose the distortion of the image of a background pattern observed through the flow is used. In order to increase the performance of the conventional Background Oriented Schlieren technique, the monochromatic background is replaced by a colored dot pattern. The different colors are treated separately using suitable correlation algorithms. Therefore, the precision and the spatial resolution can be highly increased. Furthermore a special arrangement of the different colored dot patterns in the background allows astigmatism in the region with high density gradients to be overcome. For the first time an algebraic reconstruction technique (ART) is then used to reconstruct the density field of unsteady flows around a spike-tipped model from CBOS measurements. The obtained images reveal the interaction between the free-stream flow and the high-pressure region in front of the model, which leads to large-scale instabilities in the flow. 展开更多
关键词 UNSTEADY SPIKE Flow RECONSTRUCTION Density field SCHLIEREN technique
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New Approach to Modeling a Solar Cell in Relation to Its Efficiency—Laplace Transform Technique 被引量:1
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作者 Mohamed Abdelhady Kamel El-Adawi Ibtissam Abdelrahman Al-Nuaim 《Optics and Photonics Journal》 2014年第8期219-227,共9页
Heating a solar cell subjected to incident solar irradiance is studied. Laplace Integral Transform technique is applied to get the temperature field within the cell. The efficiency as a function of the cell temperatur... Heating a solar cell subjected to incident solar irradiance is studied. Laplace Integral Transform technique is applied to get the temperature field within the cell. The efficiency as a function of the cell temperature is estimated, and its variation with the local day time is thus clarified. Different cooling levels are considered. An illustrative example is given. The results show that the diurnal temperature variation of the cell is significant, while the efficiency is revealed to be a slowly varying function of temperature along the day time. It is revealed that as the temperature of the cell increases the efficiency decreases. Thus shading and cooling conditions may be useful to increase its efficiency. 展开更多
关键词 SOLAR CELL EFFICIENCY Temperature field within a SOLAR CELL LAPLACE TRANSFORM technique
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A NEW SINGULARITY EXTRACTION TECHNIQUE FOR TDEFIE 被引量:1
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作者 Liu Feng Zhou Dongming Cai Mingjuan Ren Meng He 3iangguo 《Journal of Electronics(China)》 2007年第5期686-689,共4页
A new singularity extraction technique is presented to calculate accurately the singular integrals in Time Domain Electric Field Integral Equation (TDEFIE).In singularity extraction pro- cedure,through the aid of the ... A new singularity extraction technique is presented to calculate accurately the singular integrals in Time Domain Electric Field Integral Equation (TDEFIE).In singularity extraction pro- cedure,through the aid of the first order Taylor series of time base function including time-retardation,the singularity of the integrand can be removed.The surface current density and backscattered far-field response of a conducting cube illuminated by a Gaussian plane wave is com- puted using the presented technique.Comparisons are made with the results obtained by the Inverse Discrete Fourier Transform (IDFT) of the frequency domain and the results obtained by using Ve- chinski's time averaging technique,which demonstrate that the presented method with this new time domain singularity extraction technique to solve TDEFIE is very accurate and stable. 展开更多
关键词 Singularity extraction technique Taylor series Time Domain Electric field Integral Equation (TDEFIE)
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Characterizing large-scale weak interlayer shear zones using conditional random field theory 被引量:1
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作者 Gang Han Chuanqing Zhang +5 位作者 Hemant Kumar Singh Rongfei Liu Guan Chen Shuling Huang Hui Zhou Yuting Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第10期2611-2625,共15页
The shear behavior of large-scale weak intercalation shear zones(WISZs)often governs the stability of foundations,rock slopes,and underground structures.However,due to their wide distribution,undulating morphology,com... The shear behavior of large-scale weak intercalation shear zones(WISZs)often governs the stability of foundations,rock slopes,and underground structures.However,due to their wide distribution,undulating morphology,complex fabrics,and varying degrees of contact states,characterizing the shear behavior of natural and complex large-scale WISZs precisely is challenging.This study proposes an analytical method to address this issue,based on geological fieldwork and relevant experimental results.The analytical method utilizes the random field theory and Kriging interpolation technique to simplify the spatial uncertainties of the structural and fabric features for WISZs into the spatial correlation and variability of their mechanical parameters.The Kriging conditional random field of the friction angle of WISZs is embedded in the discrete element software 3DEC,enabling activation analysis of WISZ C2 in the underground caverns of the Baihetan hydropower station.The results indicate that the activation scope of WISZ C2 induced by the excavation of underground caverns is approximately 0.5e1 times the main powerhouse span,showing local activation.Furthermore,the overall safety factor of WISZ C2 follows a normal distribution with an average value of 3.697. 展开更多
关键词 Interlayer shear weakness zone Baihetan hydropower station Conditional random field Kriging interpolation technique Activation analysis
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Mechanical analysis of fixed geosynthetic technique of GRPS embankment
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作者 张军 郑俊杰 马强 《Journal of Central South University》 SCIE EI CAS 2013年第5期1368-1375,共8页
To overcome the deficiencies of conventional geosynthetic-reinforced and pile-supported (GRPS) embankment, a new improvement technique, fixed geosynthetic technique of GRPS embankment (FGT embankment), was developed a... To overcome the deficiencies of conventional geosynthetic-reinforced and pile-supported (GRPS) embankment, a new improvement technique, fixed geosynthetic technique of GRPS embankment (FGT embankment), was developed and introduced. Based on the discussion about the load transfer mechanism of FGT embankment, a simplified check method of the requirement of geosynthetic tensile strength and a mechanical model of the FGT embankment were proposed. Two conditions, the pile cap and pile beam conditions are considered in the mechanical model. The finite difference method is used to solve the mechanical model owing to the complexity of the differential equations and the soil strata. Then, the numerical procedure is programmed. Finally, a field test is conducted to verify the mechanical model and the calculated results are in good agreement with field measured data. 展开更多
关键词 mechanical model load transfer mechanism fixed geosynthetic technique GRPS embankment field test
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