bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of indirect agricultural losses caused by river ecological base flow protection
Authors: Tian Ruogu , Meng Zhaowei , Xu Jun , Chi Zecheng , Cui Mengxuan
Published: June 2021

In order to coordinate the relationship between ecological base flow guarantee and agricultural water use, and promote the development of ecological base flow guarantee and compensation, this paper established an evaluation system of indirect agricultural losses caused by ecological base flow guarantee. Taking the Baojixia irrigation area as an example, the substitution method was used with the social security value of urban residents as a reference, and the coefficient in combination with the income ratio of urban and rural residents was modified to obtain the social security value of rural residents’ cultivated land, then the agricultural irrigation before and after the ecological base flow guarantee was combined. The amount of water diversion was changed, finally the indirect agricultural loss caused by the protection of ecological base flow was calculated. The results show that the upper and lower limits of total agricultural indirect losses in a typical year are 420 million yuan and 122 million yuan, respectively. Actually, since the Baoji Gorge Irrigation District undertakes the task of food supply in the Guanzhong area and even in Shaanxi Province, it is necessary to consider other factors such as food security when implementing the policy of guaranteeing the base flow.
Comparison of cadmium and arsenic accumulation characteristics and remediation potential of different forage plants
Authors: Yang Jingmin , Hang Zhihong , Jiang Na , Li Zuran , Bonheur Gahonzire , Zu Yanqun
Published: June 2021

A field experiment was carried out in a farmland polluted by cadmium (Cd) and arsenic (As) in Yunnan Province to study Cd and As accumulation characteristics of 15 different forage plants, so as to screen out plants for comprehensive utilization in the farmland polluted by Cd and As. The results showed that the best growth conditions were for ‘Teosinte’ and ‘King grass’, the worst growth condition was ‘Pennisetum’. The Cd contents of shoots of ‘King grass’, ‘Sweet elephant grass’, ‘Pennisetum’, ‘Teosinte’ and ‘Alfalfa’ did not exceed the Chinese feed hygiene standard (≤ 1mg kg−1). The content of total arsenic in shoot of ‘Tall fescue’ did not exceed the feed hygienic standard (≤ 4 mg kg−1). ‘Sorghum12FS9003’ and ‘Sorghum×Sudan’ have the strongest ability to enrich Cd and As, which could be used for remediation of soil polluted by Cd and As. ‘Alfalfa’ has low Cd and As accumulation capacity.
Technical Transformation and Energy saving Analysis of Desulfurization System in Coal-fired Power Plant
Authors: Chi Ming
Published: June 2021

Taking a 200 MW coal-fired power plant in North China with a limestone-gypsum wet desulfurization system transformation project as an example, the effect of energy-saving transformation of the desulfurization system was evaluated by analyzing the impact of the transformation on the desulfurization efficiency and main energy-consuming equipment. The practice shows that the desulfurization efficiency is greatly improved and the average energy consumption of the desulfurization system is reduced by 29%, achieving the purpose of improving efficiency and saving energy.
Research on wetland change detection based on Remote Sensing
Authors: Zhang Yashuang , Wu Haiman , Liu Deli
Published: June 2021

In recent years, human disturbance and natural factors have led to great changes in the coastal wetland system of the Pearl River Delta, and the research on the changes of coastal wetland landscape pattern has become a hot topic. Based on the remote sensing data in recent 35 years, this paper studies the dynamic changes of coastal wetland landscape in the Pearl River Delta, and analyzes the driving forces of the changes of coastal wetland landscape pattern in the Pearl River Delta.
The “Lake-Canal-Irrigation District” System in Gaoyou Ancient Irrigation Project
Authors: Wang Yijia
Published: June 2021

In the practice of water control in the past dynasties in China, plain systemic thought runs through it. In Gaoyou, Jiangsu Province, the Li Canal connects Gaoyou Lake and Gaoyou Irrigation District through hydraulic facilities such as gates and dams on the east and west embankments. It realizes the deployment of water between “Lake-Canal-Irrigation District” system and takes into account irrigation and water transport. “Lake-Canal-Irrigation District” system is an open and complex system, from water storage, water transfer, water transportation, water distribution to irrigation, it is an organic whole coordinated operation, achieving dynamic balance. The “Lake-Canal-Irrigation District” system is connected, which promotes regional biodiversity and interprets the concept of sustainable development of “the harmony between man and nature”. The “Lake-Canal-Irrigation District” system solves the imbalance in the spatial and temporal distribution of water resources and improves the utilization efficiency of water resources. The systematic ancient water control projects have been enduring for a long time. Although they have evolved and developed, the basic layout structure and the principles of organization have been implemented throughout.
Analysis on variation characteristics of the minimum flow at Datong Station under the influence of the Three Gorges Reservoir
Authors: Yan Bo , Yao Liqiang , Zhang Longling , Li Jiqiong
Published: June 2021

As an important hydrological control station in the lower reaches of the Yangtze River, the Datong Station can provide guidance for regulating downstream water withdrawal activities by studying the characteristics of its changes during the dry season. This study selected the annual minimum flow index, applied linear trend method, Mann-Kendall method and wavelet analysis method to analyze its trend and periodic change characteristics, and analyzed the empirical frequency changes before and after the operation of the Three Gorges Reservoir, and obtained the following conclusions: The annual minimum flow series shows a significant increase trend, showing the characteristics of multi-period nesting in periodic changes, in which the first main period is 35-year. At the same frequency, the corresponding flow after the Three Gorges Reservoir operation was all larger than that before.
Experimental Study on Freeze-Thaw Properties and Thermal Conductivity of Green and Environment-Friendly Three-Admixture Concrete
Authors: Song Yuhao , Jin Zhengchao , Tuo Zijie , Li Chao , Fang Guangxiu
Published: June 2021

Using straw powder (rice husk ash), fly ash, silicon powder and other three admixtures to prepare concrete can improve the ecological environment and promote the reuse of agricultural and industrial wastes. In this paper, 9 groups of freeze-thaw specimens and 9 groups of thermal conductivity specimens of green and environment-friendly three admixture-blended concrete were prepared with corn, wheat and rice husk powder, replacing cement with straw powder by 6% and 8% respectively and replacing cement with fly ash by 20% and silica fume by 10%. The test results show that the mass loss rate of the concrete ranges from 0.8% to 1.4% and from 3.5% to 4.4% after 25 and 50 freeze-thaw cycles, respectively. The thermal conductivity of the concrete falls within the range of 0.2901 w/(m· K)-0.5834 w/(m·K), which is suitable for the existing building reconstruction and new construction projects in cold and severe cold areas.
Calibration Method of Biotoxicity Monitoring Sensor in Seawater Environment
Authors: Wang Jingru , Chen Long , Kong Xiangfeng , Zhang Tianpeng , Lv Jing , Xun Xiaogang , Zhang Li
Published: June 2021

The behavior of marine organisms can indicate the quality of the seawater environment. By analyzing the abnormal behavior changes of bivalve aquatic organisms, the monitoring of marine biotoxicity can be carried out. The sensor based on Hall effect can monitor the behavior changes of bivalves and provide early warning of environment pollution. This paper proposed a calibration method for biotoxicity monitoring sensor based on bivalve aquatic organisms behavior. The calibration apparatus mainly included a Z-axis fine-tuning precision lifting platform, a plastic block, and a fixed bracket of sensor probe. By manually adjusting the knob on the z-axis fine-tuning precision lifting platform, the magnet on the sensor probe moved, and the output voltage of the Hall element changed. The rational fraction fitting was used for the calibration data and the coefficient of determination reached 0.9996. Experimental results showed that the proposed calibration method could achieve high precision calibration of the bivalve aquatic organisms behavior sensor.
The research on dynamic changes of urban green spaces in Wuhan at a local scale
Authors: Wang Yuwei , Meng Xiaoliang , Wu Kaicheng , Gao Wang
Published: June 2021

Urban green spaces play a vital role in urban ecological construction and sustainable development. The primary objective of this paper is to monitor the dynamic changes of urban green spaces in Wuhan city, China from a local perspective. Combined with ArcGIS and Fragstats software, we applied two landscape metrics to detect the change process and change type of urban green spaces during two consecutive periods, 2009–2014 and 2014–2019 at pixel level. The results showed that except for few edge regions, the coverage of urban green spaces declined during 2009-2019. The urban green patches tended to be more fragmented mainly in the central part of Wuhan in the past decade. At the same time, the research results could provide reasonable decision support for the protection of urban green spaces.
Study on Russian Botanical Garden construction characteristics – on the example of Russia Northern-West botanical gardens
Authors: Budilovskaia A , Shao Y
Published: June 2021

Botanical garden is an important symbol of modern urban civilization. The botanical garden not only protects the ecological environment, but also increases the urban green space area and improves the urban environment and quality of life. This paper analyses and summarizes the construction of 12 botanical gardens of the northwest European part of Russia from three aspects: regional, cultural and plant’s characteristics. What’s more, analysing its spatial layout, concludes that it is mainly affected by the existing natural characteristics and cultural diversity. The purpose of this study is to provide reference for the development and construction of botanical garden in China.
The Application of Green Energy-Saving Technology in Building Design—Take Zhejiang Water Control Museum architectural design as an example
Authors: Wang Fang
Published: June 2021

The fundamental purpose of green building design is to protect the environment, reduce pollution and save energy. Among them, energy-saving design is the most concerned one of green building. In this paper, the architectural design of Zhejiang Water Control Museum is selected as a case study, and the optimization design of energy conservation is carried out in the aspects of building orientation design, natural wind application, roof energy conservation design, renewable energy utilization and water resource utilization. This paper comprehensively monitors the energy consumption of the whole building by combining with the building intelligent management system, and dynamically displays the current energy saving effect, emission reduction sewage and sunshade effect. We hope to establish demonstration green buildings through this project research and strengthen the application and promotion of green building energy-saving technology.
A novel two-stage partial-nitritation/anammox (PN/A) process based on zeolite biological fixed bed reactor for low-strength ammonium wastewater treatment
Authors: Gu Xiaoyang , Zheng Xuwen , Chen Yongxing , Chen Zhenguo , Meng Qingbo
Published: June 2021

A novel two-stage partial nitritation/anammox (PN/A) process coupled by a zeolite biological fixed bed reactor (ZBFB) and an anammox reactor were proposed for wastewater containing 30 mg/L NH4+-N by long-term operation. The cycle operational results by adsorption and biological desorption in ZBFB showed adsorption effluent NH4+-N maintained at 3.0-4.0 mg/L and the average biological desorption effluent NO2--N was 42.2 mg/L. In ZBFB, free ammonia inhibition on nitrite oxidizing bacteria was the main reason for stable nitrite accumulation performance with nitrite accumulation ratio as 88.70% during biological desorption step. Total nitrogen in the mixture of influent and biological desorption effluent of ZBFB could be removed to less than 15 mg/L by the subsequent anammox reactor. High-throughput sequencing analysis results presented the enrichment of Nitrosomonas and inhibition of Nitrobactor and Nitrospira in ZBFB, and dominance of Candidatua Kuenenia in anammox reactor. All results revealed desirable feasibility for nitrogen removal from low-strength ammonium wastewater by ZBFB combined with anammox reactor.
Research on the Stratification Process and Influencing Factors of Liaocheng Ancient City Based on the Translation of Historical Map
Authors: Lang Xiaoxia , Wei Guanyu
Published: June 2021

The study of historical maps is the basis for understanding the dynamic changes of cities. In this paper, the historical map of Liaocheng ancient city and other data were translated, and GIS technology was used for visual analysis. Meanwhile, combined with the concept of “stratification” in the urban historical landscape, this paper summarizes the historical evolution of the ancient city from multiple dimensions and explores the factors affecting its development in order to realize the sustainable development of Liaocheng ancient city.
Research on the protection and utilization of historical and cultural blocks under the New Museum Theory——Taking the Street Museum of Lihuangpi Road in Wuhan as an example
Authors: Chen EnYu , Xu Hong
Published: June 2021

The Street Museum is the first nationwide initiative in Wuhan to apply new museology to the protection planning of historical streets. The Lihuangpi Road Street Museum is the first street museum in Wuhan. It has played an active role in protecting historical relics, showing the unique architectural style and spatial texture of Lihuangpi Road, reflecting urban diversity, improving the living environment, and promoting the development of cultural and leisure industries effect. However, problems such as irrationality in planning and design, low follow-up investment, lack of management and supervision, and inactive participation of community residents have affected its effectiveness. Through in-depth investigations and interviews, this article summarizes the practical results and problems of the Lihuangpi Road Street Museum since its establishment, and proposes targeted opinions, with a view to providing further reference for the protection and planning of historical blocks in other cities.
Research on the construction of tourism sign system under the background of all-for-one tourism——Take Helong City, China as an example
Authors: Zhao Wenlu , Jin Guanghu
Published: June 2021

The tourism sign is a medium between tourists and scenic spots, and a window to open tourist spots. The tourism sign system is mainly to enable tourists within a certain tourism area to obtain corresponding tourism information in a timely manner, including tourism positioning, scenic spot information, play routes and other content, to provide tourists with comprehensive play services. This paper takes Helong City, Jilin Province, China as an example to discuss the planning and setting methods of tourism sign system in minority cities to aim to provide theoretical and practical basis for the application of tourism sign. According to the tourism development framework of “The all-for-one tourism planning of Helong City”, it follows the linkage radiation ring of three groups in one belt, cultural relics and ecological farms. Utilize the tourism resources of Helong City to construct a complete tourism sign system based on points, lines and surfaces to achieve a comprehensive three-dimensional network-style boutique tourism route guidance. The perfect tourism sign system provides a series of services, which can effectively help tourists make travel plans and improve the quality of tourists’ play.
Technical specifications for green design evaluation of water heater products
Authors: Zong Jianfang , Zhang Xin , Chen Haihong , Tian Jianwei , Gao Dongfeng , Yuan Han , Guan Jinxin
Published: June 2021

This paper presents the principles of green design of water heaters, analyzes the general principles of green design of water heater products, the process and key points of green design, evaluation requirements, life cycle assessment report preparation methods and evaluation methods. The technical specification of green design evaluation of water heater products has a practical supporting effect on the systematic support of the establishment of eco-design evaluation mechanism in China. The research and formulation of standards will be conducive to improving and promoting the green design ability of enterprises, enhancing the level of integrated management and cleaner production levels, thereby fostering a group of green design demonstration enterprises with green development awareness and brand influence. Meanwhile, it has positive guiding significance in leading green production and promoting green consumption.
Analysis of deformation monitoring results of a deep and large foundation pit
Authors: Yu Xinxiong , Sha Yonghua
Published: June 2021

Taking a deep and large foundation pit project as an example, the paper analyzed some developmental characteristics of its deformation during construction. The deformation included vertical displacements of the ground surface and horizontal displacements of deep soil surrounding the foundation pit. At the same time, the trends of the ground settlement were predicted based on the monitoring data. The analysis and predictions showed that: (1) The soil around the foundation pit was influenced by the excavation and supporting construction; (2) The vertical and horizontal displacements appeared some regular patterns of gradual development over time. In addition, there were certain differences in the trends of measuring points at different locations; (3) By fitting the monitoring data, the deformation of the foundation pit could be effectively predicted and offer a guidance to the engineering practice.
“Research on the Seismic Response and Analysis Method of Underground Structures Based on the Response Deformation Method”
Authors: Zheng Guodong , Yao Chenghao , Mao Mengfan , Zhai Mengxiang , Liang Tao
Published: June 2021

In order to study the underground structure under the action of an earthquake, the relationship between the displacement and the stress between layers of different soils under the action of the earthquake was carried out through the finite element numerical analysis software. The influencing mechanism of soil layer depth on the seismic response of underground structure was discussed, and the seismic response law of the system was worked out. The research results indicated that the displacement response of the soil layer structure in three directions depicted obvious laws with the change of soil layer depth. There were evident similarities and differences in the response of soils with different properties to seismic responses. These conclusions provided a certain reference for the seismic design of underground structures.
Coupling simulation of non-point source pollution and 2-D water quality in Nanhe River
Authors: Wang Ziming , Fu Rui , Wang Dongying , Zhang Xingjian , Lai Xijun
Published: June 2021

With the rapid growth of urban population and stable growth of GDP in China, non-point source pollution has become an important reason for the deterioration of urban water pollution, which seriously threatens the security of urban ecological environment. In this paper, the coupling model of non-point source pollution and two-dimensional water quality of SWMM in Nanhe region is constructed, and the coupling model is verified, and the verification results are in good agreement with the measured data. The results show that the improvement of water quality of Nanhe River by ecological treatment is limited; the load of pollutants into the river and the maximum concentration of pollutants in Nanhe River can be effectively reduced by source control and sewage interception; under the design conditions, the water quality index will be difficult to reach and recover to the original level after short-term rainfall, so it is necessary to maintain the water quality When the diversion flow is 3m3/s and 5m3/s, the Nanhe River can basically return to the level before rainfall in one day.
Selection and optimization of water filling scheme in front of super-high arch dam
Authors: Li Jintao , Tan Yaosheng , Liu Chunfeng , Liu Yang , Liu Youzhi
Published: June 2021

During the construction of super-high arch dam, the timing of water filling in front of the dam is the key link in the safety management and control of arch dam. Besides the cantilever of dam and the transverse joint aperture of concrete arch dam, the stress in the corridor area at the bottom of the dam should be considered for the timing of water filling in the dam. In this paper, Baihetan super-high arch dam project was taken as an example to study this problem, and the risk of overall dam overhang under gravity load and the influence of different water levels on the transverse joint aperture and stress in the corridor area was systematically analyzed. The research results showed that different water level elevations have obvious influence on the transverse joint aperture and stress state in corridor area, and the selection of water level elevations needs to comprehensively consider the mutual coupling relationship among these influencing factors, so as to realize the effective control of dam safety risk.
Environmental-friendly drilling fluid system in offshore natural gas hydrate formations
Authors: Zhang Yubin , Qiu Zhengsong , Zhao Xin , Ma Yongle , Mu Jiaxing , Liu Yunfan
Published: June 2021

There are abundant natural gas hydrate resources in offshore. However, the development of drilling fluid system is restricted by low ambient temperature, special formation conditions of weak cementation and high environmental protection requirements of marine discharge. In this paper, a new environmental-friendly drilling fluid system in offshore gas hydrate formations has been developed by optimizing the additives. The comprehensive evaluation shows that the freezing point of the drilling fluid can reach -10 °C, and it still has good rheological properties at 4 °C. The apparent viscosity ratio of the drilling fluid is less than 1.3, and the fluid filtration is only 4 mL. With good shale hydration inhibition, it can significantly reduce the swelling ratio and increase the cuttings dispersion recovery radio. There is no hydrate formation in drilling fluid for 24 hours at 4 °C and 10 MPa simulated conditions, which shows a good ability to inhibit gas hydrate formation. At the same time, compared with the experimental fluid without hydrate decomposition inhibitor, the drilling fluid can delay hydrate decomposition. In addition, the drilling fluid has good environmental protection performance, which can meet the requirements of high environmental protection in offshore.
Study on Shaking Table Test of Underground Substation Considering Soil-Structure-Equipment Interaction
Authors: Zheng Hongyu , Wen Bo
Published: June 2021

The electrical equipment has a large quality proportion, and the interaction between equipment and structure cannot be ignored, especially under seismic loads. A 1/25 scale model was designed and made for shaking table test to study its seismic performance, and the acceleration and displacement responses of soil, structure and equipment under unidirectional and bidirectional ground motions were analyzed respectively. The test results show that the acceleration response of the structure and soil increases gradually from bottom to top under the soil-structure-equipment interaction. The acceleration response of equipment is greater than that of the floor where it is located, and it is greater at the position of the side column than that at the position of the central column. The acceleration amplification factor of the soil adjacent to the structure is much larger than that of the soil far away from the structure relative to that at the bottom of the layered shear box.
The earthquake under the action of underground structure and the influence of the distance between adjacent buildings
Authors: Liu Pengjun , Zheng Guodong , Zhang Qishuo
Published: June 2021

With the large-scale construction of urban rail transit in China, subways often cross the bottom of surface buildings or are located near them. In order to study the complex catastrophic correlation effects of the underground structure of the subway, the soil and the adjacent existing structures under earthquakes. We carried out numerical simulation calculations to study the effects of underground structures and adjacent existing structures under earthquakes. The interaction law of nearby existing buildings, the influence mechanism of the neighboring building’s depth factors on the seismic response of the complex system, and the system’s seismic response law were determined.
Moisture Content Distribution and Variation Law of Highway Subgrade in High-Latitude and Low-Altitude Deep Seasonal Frozen Ground Region
Authors: Gao Wei , Sun Wei , Wang Xu , Dong Naibao
Published: June 2021

According to the tracking observation of the highway subgrade moisture content in the high-latitude and low-altitude seasonal frozen ground region in Heilongjiang province, the time-varying variation law of the subgrade moisture content and the distribution state of the subgrade moisture content at different depths are analysed to confirm that the distribution pattern of moisture content in fine-grained soil subgrade does not strictly conform to capillary ascent distribution law of groundwater (or surface water), which is related to the coverage and gap of the pavement, slope water seepage and water-holding capacity of the subgrade soil. In general, the distribution state can be roughly divided into B distribution, C distribution, D distribution and S distribution. As the distribution of subgrade moisture content is no longer the conventional pattern of “low up and high down”, the control of subgrade height should not be rigidly stuck to the subgrade height controlled by capillary ascent height, while multiple measures should be taken to ensure water temperature and strength stability of subgrade.
Calculation of common evaluation indexes for heritage evaluation of water conservancy projects
Authors: Lu Bing , Yao Jianfeng , Ding Mengjiao , Chen Siyu , Wang Hanxiao
Published: June 2021

In this article, through further study of water conservancy engineering heritage, compiled a set of system of water conservancy engineering heritage research evaluation methods, namely analytic hierarchy process (AHP) method combined with the Delphi evaluation, through this research, hope that through quantifiable data model and offer reference for evaluation of the water conservancy engineering heritage. Thus, the system protection, effective management and rational utilization of water conservancy heritage can be better promoted.
An Effectiveness Study of SPC Control Charts on the Quality Control for Construction in Asphalt Pavement
Authors: Xu Zhiyong , Zhou Qiang , Chen Gang , Wang Yun , Yang Xiongwei , Liu Zhen
Published: June 2021

Aiming at the problems of insufficient dynamic control and data mining of Expressway pavement construction quality in Yunnan, this paper analyzes the application of Exponentially Weighted Moving Average (EWMA) control chart in dynamic control of Expressway asphalt pavement construction quality. Firstly, the quality characteristic value of pavement construction is defined as the data type of multiple variation sources, and the mathematical model of multiple variation sources is studied to solve the problem of excessive false alarm. Then, on the theoretical basis of statistical process control (SPC), the paper compares and analyzes the three control chart schemes of traditional Hugh Hart control chart, Tabular Cumulative Sum (CUSUM) control chart and EWMA control chart, and concludes that the application effect of EWMA control chart is obviously better than the other methods in the aspects of applicability and inspection output. Finally, combining with the measured data of asphalt mixture temperature and asphalt weight in pavement construction, EWMA control diagram is used to carry out practical research, and the results are better.
The Standardization System of Water Conservancy Project Cost Management under the EPC General Contract Mode
Authors: Li Sha , Wang Yijia , Zeng Yu
Published: June 2021

It is the development trend for water conservancy project to adopt EPC general contract mode. The realization of scientific and effective project cost management under total price contract is the key to guarantee the contractor’s economic benefit. Based on the contractor’s perspective, this paper sorts out the content of cost management at each stage, clarifies the responsible subject of cost management at each stage, and explores the construction of cost management standardization system.
Turbidity Removal of Landscape Water by Filtration Bed with Suspended Media
Authors: Zhang B H , Ren Y X , Liu H , Guo D , Shao Y H
Published: June 2021

High turbidity seriously affects the landscape effect of urban landscape water. In order to explore the turbidity removal effect of filtration bed with suspended media materials on landscape water, a filtration test was carried out with Xinhe river in Fengxi new city. The results showed that the filter bed had an effective and reliable removal performance on turbidity and suspended solids in landscape water. The turbidity removal rates were 44.50%-77.24%, and the suspended solid removal rates were 50.37%-78.85%. The use of expended polystyrene filter media material and upward flow direction got higher remove effect of the turbidity. Suspended solid particles with size less than 100 μm is the limiting factor affecting the treatment effect of the filter bed, and the expanded polystyrene filter material had a better removal effect on the particulate matter in this range. On the premise of ensuring the treatment effect, the filter bed with suspended media has the advantages of low backwash energy consumption and long filtration period, therefore, it is suitable to be used as the pre-treatment unit of landscape water treatment project.
The characteristics of internal and accumulated pores of calcareous sand
Authors: Yu J. Y. , Gao Y. , Li W. L. , Chen Q.
Published: June 2021

Calcareous sand is characterized by irregular shapes and high porosity, which makes its engineering properties more special. Based on the calcareous sand from a reef island in the South China Sea, the characteristics of the internal pores and the accumulated pores between the calcareous sand particles were explored by a microscopic system and image analysis techniques. The results show that for calcareous sand particles with different particle sizes, the distributions of internal pores and accumulated pores follow the exponential distribution. The probability distribution of internal pores is the same as that of accumulated pores, and the area of accumulated pores between particles is about 100 times that of internal pores of particle itself. The characteristics of accumulated pores are affected by the size and shape of the particles.
Dynamic performance of a new type of damping and wind-resistant bearing in the Nizhou waterway bridge of Nansha Bridge
Authors: Zhou X D , Zhu P , Zhang X M
Published: June 2021

In order to optimize the transverse structural system of the 1688m long-span steel box girder suspension bridge (Nizhou waterway bridge of Nansha Bridge), a new type of lateral damping energy-consuming wind-resistant bearing is proposed, and the quasi-static test is carried out. Also, the nonlinear time-history analysis method is used to compare and analyze the influence of the lateral fixed restraint and the new lateral damping energy-consuming wind-resistant bearing on the bridge tower internal force, main beam internal force, main beam displacement and rotation angle of the long-span suspension bridge. The research results show that, the new lateral damping energy-consuming wind-resistant bearing has good hysteretic energy consumption; compared with the conventional wind-resistant bearing, the seismic performance is better than the pylon which setting the horizontal fixed constraint, transverse bending moment of the pylon is smaller when adopting the new lateral damping energy-consuming wind-resistant bearing. The shearing force and bending moment of the main beam are obviously smaller than the transverse fixed restraint system, and decrease with the increase of the stroke of the bearing; the use of the new lateral damping wind-resistant bearing has little effect on the lateral displacement and rotation angle of the main beam.
Shear strength assessments of residual soil for Ia Pet wind power project in Vietnam
Authors: Wang Kuanjun , Li Linxian , Shen Kanmin , Ma Lili , Jin Junwu , Shi Ting
Published: June 2021

The geotechnical parameters are of great importance in wind turbine foundation design. As a case study, laboratory test results of Ia Pet wind power project in Vietnam were analysed to accurately estimate the strength of residual soil, which is classified as high plasticity silt (MH). Due to sample disturbance, the undrained shear strength s
u from triaxial unconsolidated undrained shear test (UU) is absolutely underestimated, while su from direct quick shear tests (DSq) and triaxial consolidated undrained shear test (CU) are more representative. Good linear correlations have been found between soil depth and strength obtained from DSq and CU tests. The normalised undrained shear strengths s
u/σ
v0’ indicate that the residual soil at 0m to 8m is heavily overconsolidated, where s
u/σ
v0’ is larger than 0.4. Furthermore, the normalised undrained shear strengths s
u/σ
v0’ presented negative linear correlation of liquidity index, which can be used to quick and cautious estimate the strength of Ia pet residual soil in the future by using liquidity index. The undrained shear strength evaluation using liquidity index is in good agreement with DSq and CU test results, which preliminarily verifies the applicability of expression between s
u/σ
v0’ and I
L.
Quality and safety issues and countermeasures of major water conservancy projects in Zhejiang Province
Authors: Wang L , Xie Z K , Chen W L , Fu H W
Published: June 2021

Water conservancy project is an important public infrastructure project related to the national economy and people’s livelihood. The quality and safety issues of major water conservancy projects are the core work for the government to strengthen the management of water conservancy project construction. Based on the inspection and re-inspection work of major water conservancy projects in Zhejiang Province between 2015 and 2019, this paper analyzes the main problems existing in major water conservancy projects, points out the engineering quality and safety problems account for a large proportion, analyzes the changing trend of engineering quality and safety problems, points out the main causes of quality and safety problems as well as the causes of non-correction, and puts forward the corresponding solutions. On this basis, the main responsible parties and problems are analyzed, which provides reference and suggestions for the relevant participating units to strengthen the quality and safety management of major water conservancy projects in the future.
Wave Characteristics in Northeast Coastal Waters of Zhoushan Island Under the Influence of Winter Monsoon
Authors: Yang B , Xie H W , Ding J , Yang W K , Huan F , Ou J
Published: June 2021

Waves at 12 m water depth in the northeast coastal waters of Zhoushan Island were measured from November 2014 to February 2015, and the characteristics were described. The study showed that the significant wave height varied from 0.08 to 1.35 m with the average of 0.36 m during the winter monsoon period, but the maximum of the maximum wave height is close to the maximum value of some typhoon waves of the same place. The monthly main wave direction varied from ENE to N to NE to ENE. Relatively high correlations exist between some wave parameters and relationships between them were identified. Most of the waves have a bimodal spectrum and the influence of monsoon on waves is intermittent.
Research and prospect of post-peak strain-softening characteristics of rocks
Authors: Xu Guo-Ping , Liu Hong-Zhou , Fu Bai-Yong , Yu Jian-Gang
Published: June 2021

The current research status and development trends are summarized in order to analyze the strain softening deformation characteristics of post-peak of rocks, and the corresponding key problems are found, the key issues included the influence of strain softening on tunnel engineering and the research status of strain softening in hydraulic engineering. Based on the existing researches, it is found that there are few studies on the deformation characteristics of post-peak of rocks, and there is a lack of damage constitutive model which can better describe the post-peak mechanical properties. At present, it is impossible to simulate the influence of rock softening on stiffness degradation in indoor tests, and there is also a lack of on-site construction measured data as support; at the same time, the surrounding rock control and protection technology under loading and unloading also urgently needs to be improved; in addition, the interaction mechanism between water and structure during rock softening with water needs to be further explored.
Study on Key Technologies of Ecological Civilization of Lishui Ancient City Water System
Authors: Gong Mengyuan , Ye Zhou
Published: June 2021

Starting from the historical dimension, this paper studies the historical documents and engineering cases of ancient water conservancy projects in Lishui, explores the transformation law of urban water system in Lishui, and summarizes the key technologies of water ecology contained in ancient water control practice. It was found that Chuzhou took advantage of geographical, geological and climatic conditions, followed the overall balanced water control strategy, planned the ancient city water system network, and completed the task of water distribution. Among them, guided by planning technology, supplemented by canal system network, water and sediment regulation, flood control, interchange diversion and other technologies, a perfect water system is finally formed, which can provide reference for modern water conservancy projects construction.
The Safety Automatic Monitoring System of Ancient Seawall Based on Vibration Control
Authors: Wang Jianhua , Li Shuyi , Hu Zhichao
Published: June 2021

With the development of Chinese economy and society, infrastructure and engineering construction projects continue to increase. There are often construction projects such as wharfs, bridges and houses in the areas near the ancient seawall, which will affect the ancient seawall to a certain extent. Using IoT automated monitoring methods to realize the remote real-time monitoring and early warning of the ancient seawall of Qiantang River, and analyze the impact of vibration caused by the construction on the ancient seawall. In the mean time, safety automatic monitoring system of the ancient seawall based on vibration control was developed. The paper through the application of three experiment cases, analyze the impact of construction near the seawall, which has certain application value for the protection of the ancient seawall, daily operation management, and construction guidance of projects near seawalls.
Path analysis of water use efficiency in water diversion and irrigation areas in the lower Yellow River
Authors: Feng Feng , Zhang Fang , Zhao Ting , Jiang Nan , Wang Mengzhen , Feng Yuehua
Published: June 2021

The evaluation of water use efficiency is a comprehensive and continuous evaluation of irrigation water use efficiency in an irrigation district. The relationship between the main impact factors can effectively improve the accuracy and rationality of the results. Based on the data from 2005 to 2014 in the Yellow River irrigation area of the lower reaches of the Yellow River, this paper determined the direct effect, indirect effect, determination coefficient of the eight quantitative impact factors, as well as the difference of total contribution to R2, through the mathematical method of path analysis. Through the calculation data and analysis, it is found that the completion rate of supporting facilities is the most important influencing factor for the water use efficiency of the water diversion and irrigation areas in the lower Yellow River. The completion rate of supporting facilities also plays a role in the investment of water-saving projects, channel length and channel lining rate, which plays a significant role of water diversion and irrigation areas in the lower Yellow River. and the least influential factor is precipitation. The above studies have identified the existing problems and weak links in the process of water resources management in the Yellow River Diversion Irrigation Area, providing technical support for the scientific planning and sustainable development of the Yellow River Diversion Irrigation Area in the next step.
Study on construction technology of percussive reverse circulation drilling hole forming squeezed branch pile
Authors: Zeng Jun-Yan , Li Hai-Qin , Guan Wei-Dong , Zhu Wen-Tong
Published: June 2021

Taking No.65 pier of Zhongshan-Tanzhou express line as the background, the construction technology of percussive reverse circulation drilling hole forming squeezed branch pile is studied, the construction process of percussive reverse circulation drilling hole forming squeezed branch pile is defined, and through the field trial hole forming test, the points needing attention in field construction are summarized and improved: (1) The top elevation of the steel casing shall not exceed 30cm of the surface elevation, and the hole diameter of the percussion drilling hole shall be slightly larger than the designed hole diameter, so as to avoid the floating of the steel cylinder and the influence of too small hole diameter on the squeezing operation; (2) hole cleaning operation is an important factor for the success or failure of the squeezed branch pile construction, and the sediment thickness has a great influence on the bearing capacity of the pile foundation. After the expansion equipment is squeezed and the reinforcement cage is lowered, the hole cleaning is carried out, and the control points and mud parameters during each hole cleaning are clarified; (3) during the expansion process, the extrusion pressure value and the floating amount of the expansion equipment should be detailed, the geological information should be verified, and the bearing capacity of the pile foundation should be evaluated.
Study on Ultimate Seismic Capacity of Concrete Gravity Dam-Superhigh Face Rockfill Dam Compound Structure
Authors: Liu Jing , Zhou Heng , Lu Xi , Di Shengjie , Xing Ruijiao
Published: June 2021

Based on a very high for the project of the concrete face rockfill dam, by three-dimensional finite element analysis method, from the seismic permanent deformation, stress, deformation and stability of dam slope angle of joint panel, this paper demonstrates the ultimate seismic capacity of concrete gravity dam - superhigh face rockfill dam compound structure, the research results show that the dam seismic permanent deformation limit aseismic capacity from 0.65 g to 0.72 g, panel stress seismic limit of 0.7 g, joint dislocation of aseismic capacity limit is 0.8 g, dam slope stability of aseismic capacity limit is 0.43 g. The seismic ability of concrete gravity dam - superhigh face rockfill dam compound structure is strong and can meet the local fortification intensity requirements.
Research on the Application of Step-pool System in Ancient Irrigation Engineering
Authors: Wang Yijia , Gao Lihui , Yao Jianfeng
Published: June 2021

The “step-pool system” is a common river topography in mountain rivers. In the application for Heritage Irrigation Structures in 2020, an artificial “step-pool system” built two thousand years ago was shown to the world, which is located in the 36 Weirs of Baishaxi Stream in Wucheng District, Jinhua City, Zhejiang Province. The creator of this ancient irrigation project used the ideas of “Building weirs by ponds” and “Distributed river development” on the Baishaxi stream, which spans 45 kilometers from the end to the end and has a vertical drop of 168 meters, to build this multifunctional ancient super barrage group project. Their experience and insights coincide with modern engineering theories, which have changed the natural characteristics of the river and made positive changes in the ecological environment of the river basin in a direction that is beneficial to human life.
Identification of pulse-like ground motions during the 1994 Northridge Earthquake
Authors: Han Lu , Tao Zhengru , Wang Xinyan
Published: June 2021

The 1994 Northridge Earthquake is selected as an example to discuss the ability of three pulse-like ground motion identification methods. Wavelet analysis, peak-point method (PPM) and zero velocity point method (ZVPM) are used. Pulse indictor (PI) is calculated to identify pulse-like ground motions from 314 near-fault records. Peak ground velocity (PGV) and pulse period (T

p
) of the pulse-like motion from these three methods are compared. Most of the pulse periods from PPM are smaller than those from the other two methods. And, most stations with pulse-like ground motions are located on the hanging wall. The effect of velocity pulse on response spectra is investigated further. The amplification at the hanging wall stations is more serious than that at the footwall stations.
Construction Method of Evaluation System of Water Conservancy engineering Heritage
Authors: Ding Mengjiao , Yao Jianfeng , Li Wenye , Lu Bing , Wang Hanxiao , Chen Siyu
Published: June 2021

At present, socialism with Chinese characteristics has entered a new era, and the reform and development of water conservancy is facing new situations, new tasks and new requirements. With the establishment of the list of “Heritage Irrigation Structures” in 2014, the ancient irrigation system in China has been gradually excavated, and the irrigation engineering heritage of our country has reached 23 items. The protection and display and utilization of ancient irrigation heritage is conducive to transforming the advantages of historical and cultural resources into social and economic advantages and promoting the development of local economy. Through the collection of literature and field research, this article deeply studies the formation and characteristics of water conservancy project heritage, analyzes the value composition of water conservancy project heritage, and summarizes and extracts the indexes of water conservancy project heritage value, and this paper points out the principles of selecting index items. In this paper, the index system is divided into target layer, criterion layer, supplementary criterion layer and index layer. The target layer is five values, the criterion layer is the specific classification of the target layer, the supplementary criterion layer is the corresponding supplement of the criterion layer, and the index layer is the quantification of the criterion layer.