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Modeling of hydrological processes in arid agricultural regions

Jiang LI,Xiaomin MAO,Shaozhong KANG,David A. BARRY

《农业科学与工程前沿（英文）》 2015年第2卷第4期页码 283-294 doi: 10.15302/J-FASE-2015076

摘要： Understanding of hydrological processes, including consideration of interactions between vegetation growth and water transfer in the root zone, underpins efficient use of water resources in arid-zone agriculture. Water transfers take place in the soil-plant-atmosphere continuum, and include groundwater dynamics, unsaturated zone flow, evaporation/transpiration from vegetated/bare soil and surface water, agricultural canal/surface water flow and seepage, and well pumping. Models can be categorized into three classes: (1) regional distributed hydrological models with various land uses, (2) groundwater-soil-plant-atmosphere continuum models that neglect lateral water fluxes, and (3) coupled models with groundwater flow and unsaturated zone water dynamics. This review highlights, in addition, future research challenges in modeling arid-zone agricultural systems, e.g., to effectively assimilate data from remote sensing, and to fully reflect climate change effects at various model scales.

关键词： hydrological processes irrigation area SPAC crop growth groundwater canal seepage

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Hydrocele of the canal of Nuck — an old problem revisited

null

《医学前沿（英文）》 2013年第7卷第4期页码 517-519 doi: 10.1007/s11684-013-0300-4

摘要：

Herein the authors describe the case of a young woman presenting with a tender lump in her groin. Clinically the differential was of either a reactive lymph node or a femoral hernia. Ultrasound scan was urgently arranged and showed a cystic lesion. Surgical exploration was carried out and revealed this to be a hydrocele of the canal of Nuck. This was excised and the patient’s symptoms resolved and she was discharged home the following day. We explore the embryology, pathophysiology and management of this rare entity.

关键词： canal of Nuck hernia embryology

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Scientific significance of ancient maps of Yellow River and Grand Canal for water conservancy in China

Xiaocong LI,

《结构与土木工程前沿（英文）》 2009年第3卷第4期页码 445-454 doi: 10.1007/s11709-009-0063-9

摘要： Based on the study of ancient maps preserved in China and abroad, the systematic nature and practical meaning of the maps of the Yellow River and Grand Canal is demonstrated. It is pointed out that the ancient maps not only record the spatial information of the established water conservancy engineering for river harnessing but also the management systems of the rivers in history. Besides, the maps provide abundant information on nature, humanity, and geography and possess high value in academic research and art appreciation.

关键词： information management established appreciation practical

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Foundations bearing capacity subjected to seepage by the kinematic approach of the limit analysis

Mehdi VEISKARAMI, Ghasem HABIBAGAHI

《结构与土木工程前沿（英文）》 2013年第7卷第4期页码 446-455 doi: 10.1007/s11709-013-0227-5

摘要： An estimate of the ultimate load on foundations on soil layers subject to groundwater flow has been presented. The kinematic approach of the limit analysis was employed to find the upper-bound limit of the bearing capacity. Both smooth and rough base strip foundations were considered associated with different collapse patterns. Presence of the groundwater flow leads to a non-symmetric collapse pattern, i.e., a weak side and a strong side in two-sided collapse patterns, depending on the direction of the flow. It was found that the bearing capacity has a decreasing trend with increase in the groundwater flow gradient and hence, a reduction factor has been introduced to the third term in the bearing capacity equation as a function of the flow gradient.

关键词： foundation bearing capacity limit analysis numerical computation plasticity seepage

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Surficial stability analysis of soil slope under seepage based on a novel failure mode

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 712-726 doi: 10.1007/s11709-021-0729-5

摘要： Normally, the edge effects of surficial landslides are not considered in the infinite slope method for surficial stability analysis of soil slopes. In this study, the limit stress state and discrimination equation of an infinite slope under saturated seepage flow were analyzed based on the Mohr-Coulomb strength criterion. Therefore, a novel failure mode involving three sliding zones (upper tension zone, middle shear sliding zone, and lower compression zone) was proposed. Accordingly, based on the limit equilibrium analysis, a semi-analytical framework considering the edge effect for the surficial stability of a soil slope under downslope seepage was established. Subsequently, the new failure mode was verified via a numerical finite element analysis based on the reduced strength theory with ABAQUS and some simplified methods using SLIDE software. The results obtained by the new failure mode agree well with those obtained by the numerical analysis and traditional simplified methods, and can be efficiently used to assess the surficial stability of soil slopes under rainwater seepage. Finally, an evaluation of the infinite slope method was performed using the semi-analytical method proposed in this study. The results show that the infinite slope tends to be conservative because the edge effect is neglected, particularly when the ratio of surficial slope length to depth is relatively small.

关键词： soil slope seepage surficial failure mode stress state edge effects

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Quantification of seepage in a multi-layered disconnected river-aquifer system

Jiang LI, Haizhu HU, Xiaomin MAO, Yi LIU

《农业科学与工程前沿（英文）》 2017年第4卷第2期页码 237-245 doi: 10.15302/J-FASE-2017135

摘要： Quantification of seepage in disconnected river-aquifer systems is significant for local water management and groundwater pollution control, especially in areas with water shortage or contamination. The vadose zone under riverbeds usually exhibits a multi-layered structure, particularly when paved with low permeability liners. To evaluate the impact of engineering solutions to seepage under such conditions, we proposed an approach by combining GIS and the minimum flux in saturation layer (MFSL) method. MFSL can calculate the stable seepage rate by assessing the dominant low permeability layers (including but not limited to the liners) in multi-layered disconnected river-aquifer systems. We used MFSL to calculate local seepage rate, and used GIS to extend the results to a regional scale. The reliability of MFSL is discussed by comparing the results with the double ring infiltration test, the numerical simulation by HYDRUS, and the methods of stream package in MODFLOW, including its improved form. A case study was conducted in the Yongding River with river-aquifer seepage calculated under various conditions, including different river water levels (i.e., under the designated water level, drought stage level, flood stage level and flood inundation level) and with/without low permeability liners (i.e., ecological membranes or geomembrane). Results showed that low permeability liners could greatly reduce the seepage rate. However, if an unlined inundation area exists, the seepage rate may increase greatly. The results indicated that the proposed method was reliable and convenient for calculating long-term, large area seepage in disconnected river-aquifer systems especially those paved with liners.

关键词： infiltration low permeability liner multi-layered porous media river-aquifer seepage

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Seepage analysis of Upper Gotvand Dam concerning gypsum karstification (2D and 3D approaches)

Jamshid SADREKARIMI, Majid KIYANI, Behnam FAKHRI, Mohammad Javad VAHDATIRAD, Amin BARARI

《结构与土木工程前沿（英文）》 2011年第5卷第1期页码 71-78 doi: 10.1007/s11709-010-0083-5

摘要： Upper Gotvand Dam is constructed on the Karun River at the south west of Iran. In this paper, 2D and 3D models of the dam together with the foundation and abutments were established, and several seepage analyses were carried out. Then, the gypsum veins that are scattered throughout the foundation ground were included in the models, and the seepage pattern, considering the dissolution law of gypsum, was analyzed. It was disclosed that the discharge fluxes obtained from 2D and 3D analyses are not similar, and the discharge flux in 3D model is about four times that of the 2D model. Also, the 3D model locates the phreatic surface somewhat higher than the 2D model. This means that the 2D model estimates lower pore water pressure pattern in comparison with the 3D model. These may be attributed to the fact that with 2D model the lateral components of vectors of seepage velocity are ignored. In the current case, the rate of increase of discharge flux due to dissolution of gypsum veins was obtained to be a third-order function of the aperture width. In spite of the fact that the grout curtain is designed to be about 170 m deep, however, complete dissolve of gypsum will severely increase the discharge flux through the foundation ground.

关键词： Upper Gotvand Dam seepage analysis gypsum veins 3D model discharge flux

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Synchronous rectal adenocarcinoma and anal canal adenocarcinoma

GU Jin, YAO Yunfeng, LI Jiyou, LU Aiping, WANG Hongyi

《医学前沿（英文）》 2007年第1卷第3期页码 333-337 doi: 10.1007/s11684-007-0064-9

摘要： It is difficult to distinguish a rectal carcinoma with anal metastases from coexistent synchronous anorectal carcinomas. The therapeutic strategy for rectal and anal carcinoma is so different that it should be clearly identified. Here, we report on the case of a 63-year-old man who presented with an upper-third rectal adenocarcinoma. Five months after resection, he developed an adenocarcinoma in the anal canal. The histological slides of both tumors were reviewed and immunohistochemical studies for cytokeratins (CKs) 7 and 20 were performed. The index tumor demonstrated CK 7 /CK 20+ and the second showed CK7+/CK20+. For this reason, we believe the present case had synchronous adenocarcinomas arising from anal canal and the rectum separately. It is very important to differentiate the anorectal lesions pathologically because of the impact on the therapeutic options available, especially for the lesion arising in the anal canal.

关键词： CK7+/CK20+ resection different therapeutic strategy upper-third

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Permeability analysis and seepage process study on crystal layer in melt crystallization with fractal

Xiaobin JIANG, Baohong HOU, Yongli WANG, Jingkang WANG

《化学科学与工程前沿（英文）》 2011年第5卷第4期页码 435-441 doi: 10.1007/s11705-011-1139-3

摘要： In this paper a porous media seepage model was applied to analyze the permeability and study the seepage process of crystal pillar formed in the preparation of electronic grade phosphoric acid (EGPA). By inspecting the seeping process, the structure parameter of crystal pillar could be obtained. Two basic ideal models (perfectly separated model and perfectly connected model) were presented and a characterized factor was introduced to modify the model. A good simulation result was obtained which met the experiment result well. The relationship between and permeability were also discussed. The characterized factor showed potential application on optimizing process.

关键词： melt crystallization porous media fractal permeability hyperpure material simulation

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Application of entropy-based fuzzy matter-element analysis in seepage monitoring of RCC dam

Chongshi GU, Zhijun ZHANG, Xin CAI, Yue HOU

《结构与土木工程前沿（英文）》 2011年第5卷第1期页码 105-111 doi: 10.1007/s11709-010-0015-4

摘要： Taking account of the fuzzy results of the seepage monitoring analysis of roller compacted concrete (RCC) dam and uncertainties of the individual indicator evaluation, the fuzzy matter-element model of seepage monitoring of RCC dam analysis has been established with the use of the fuzzy matter-element analysis theory and the concept of euclid approach degree. The use of entropy theory can calculate the weighting factor through the disorder utility values of the information reflected by the data itself, which can effectively avoid the problems of weight distribution and uncertainties of subjective judgments of the seepage monitoring analysis of roller compacted concrete dam. And further the example shows that the analysis of entropy-based fuzzy matter-element analysis model of the seepage monitoring of roller compacted concrete dam is in accordance with the actual situation, which verifies the effectiveness of the method.

关键词： information entropy fuzzy matter-element roller compacted concrete (RCC) dam seepage analysis

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渠网恒定流及非恒定流数学模型的研究及应用

张明亮,沈永明

《中国工程科学》 2007年第9卷第8期页码 92-96

摘要：

从求解一维圣维南方程组的Preissmann 4点隐式差分格式出发, 建立了一维河网及渠网数学模型，并对计算中所涉及的一些关键技术问题进行了较为详细的阐述。利用模型对树状渠网的恒定流及复杂的环状渠网和河网的非恒定流对模型进行验证。验证结果表明，水位和流量过程计算值与Islam的计算值吻合较好，各渠道的流量分配计算结果精度也较高，为河网及渠网的水量调度提供了一个较为简便实用的工具，为建立渠网及河网的综合水质生态数学模型打下基础。

关键词： Preissmann格式渠网及河网流量分配水质模型

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Seepage failure by heave in sheeted excavation pits constructed in stratified cohesionless soils

Serdar KOLTUK, Jie SONG, Recep IYISAN, Rafig AZZAM

《结构与土木工程前沿（英文）》 2019年第13卷第6期页码 1415-1431 doi: 10.1007/s11709-019-0565-z

摘要： In this study, experimental and numerical investigations are performed to clarify the seepage failure by heave in sheeted excavation pits in stratified cohesionless soils in which a relatively permeable soil layer ( ) lies above a less permeable soil layer ( ) between excavation base and wall tip. It is shown that the evaluation of base stabilities of excavation pits against seepage failure by using Terzaghi and Peck’s approach leads to considerably lower critical potential differences than those obtained from the model tests. On the other hand, a relatively good agreement is achieved between the results of the model tests and the finite element (FE) analyses. Further investigations are performed by using axisymmetric excavation models with various dimensions and ground conditions, and a comparison between the results obtained from Terzaghi and Peck’s approach and finite element analyses is given.

关键词： seepage failure by heave cohesionless stratified soil model test Terzaghi and Peck’s approach FE analysis

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Embankment dam foundation analysis for the decrease of internal erosion likelihood

Marc SMITH

《结构与土木工程前沿（英文）》 2012年第6卷第4期页码 431-436 doi: 10.1007/s11709-012-0183-5

摘要： A zoned embankment dam is founded on clay underlain by a sand deposit. Major seepage phenomena were noticed in the foundation downstream from the dam where the vertical seepage forces in the sand layer were expected to exceed the downward forces due to the overlying clay. Modern technologies were applied to delineate critical zones to help design optimal rehabilitation measures. A global electromagnetic survey was carried out to detect and map the main sources, pathways and exits of seepage. Based on these global findings, a more detailed analysis was then conducted to identify zones where thickness of the foundation clay is minimal, pore pressures in sand are higher and thus where the factor of safety against uplift is lower and internal erosion is more likely to occur. Clay thickness evaluation required the determination of land surface as well as clay-sand contact elevations. A laser airborne survey was performed to model the land surface elevation. Data concerning the clay-sand contact elevation came from the interpreted stratigraphy based on a series of boreholes and cone penetration tests. This data was combined in a geostatistical model along with the measured piezometric levels in the foundation. This resulted in a contour map showing factors of safety against uplift over the entire downstream area. The use of modern technologies, namely electromagnetic and laser surveys as well as geostatistical tools, was instrumental in defining the limits of an otherwise spread-out problem and to provide an optimal solution, in terms of costs and effectiveness, for the long-term stabilization of the foundation.

关键词： seepage detection geostatistical analysis dam monitoring internal erosion LIDAR survey

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Recent development in biogeotechnology and its engineering applications

《结构与土木工程前沿（英文）》 2021年第15卷第5期页码 1073-1096 doi: 10.1007/s11709-021-0758-0

摘要： Microbial geotechnology or biogeotechnology is a new branch of geotechnical engineering. It involves the use of microbiology for traditional geotechnical applications. Many new innovative soil improvement methods have been developed in recent years based on this approach. A proper understanding of the various approaches and the performances of different methods can help researchers and engineers to develop the most appropriate geotechnical solutions. At present, most of the methods can be categorized into three major types, biocementation, bioclogging, and biogas desaturation. Similarities and differences of different approaches and their potential applications are reviewed. Factors affecting the different processes are also discussed. Examples of up-scaled model tests and pilot trials are presented to show the emerging applications. The challenges and problems of biogeotechnology are also discussed.

关键词： biogeotechnology biocementation bioclogging biogas strength enhancement liquefaction mitigation seepage control

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环境同位素示踪方法研究新安江右坝肩绕坝渗流

陈建生,刘建刚,董海洲,陈亮

《中国工程科学》 2004年第6卷第1期页码 57-63

摘要：

通过分析新安江右坝区环境水中的同位素²H，¹⁸O，³H以及温度与电导分布，研究新安江右坝存在的绕坝渗流场。环境同位素数据证实了右坝肩基岩中存在着绕坝渗漏，排水廊道中的排水既有边坡降雨入渗，又有库水的绕坝肩补给，排水廊道扇形孔中的渗水完全来自于绕坝肩的库水渗漏。3E_1-1扬压力升高的原因是由于F0断层渗漏造成的结果，但6坝段和7坝段下部的F1断层基本上不存在渗漏,灌浆廊道G7-4排水孔中渗水中的³H高达19.54TU，证实该渗漏水来自坝后区的降雨补给。右坝肩观测孔R3和R6等孔中发现绕坝库水成分，环境同位素数据同时证实了人工示踪方法得到的结论。

关键词：环境同位素绕坝渗流大气降水水库