The circular saw cutting slope has requirements on high excavation quality,little disturbance to slope rock mass and high slope stability.But the selection of slope cutting and excavation parameters is mainly based on the experience of operators so far,which restricts the application of the technology.Based on the mechanical mechanism of circular saw cutting and breaking rock,this paper adopts PFC3 D discrete element model to study the meso-mechanism of circular saw cutting and breaking rock,then it analyzes the key factors affecting the stability of slope.The results show that the forward speed and cutting depth of the saw blade are positively correlated with the damage degree of the slope rock mass.The larger the forward speed and cutting depth are,the more cracks are produced and the greater the damage to the slope rock mass is.There is little difference in the force of the saw blade between multiple cutting and single cutting at the same depth,but the number and range of cracks produced by multiple cutting are smaller than that of single cutting,that is,the damage to rock mass is smaller by multiple cutting.Rotation speed and direction have little influence on rock breaking effect.The research results could provide reference and basis for cut-ting and excavation of rock slope with circular saw.
In order to obtain a special airfoil for vertical axis wind turbines with good aerodynamic perform-ance and quantification,and to optimize the design of the airfoil with the method of combining the agent model with the genetic algorithm,an optimization algorithm with global convergence characteristics is pro-posed by using the agent model and the method of the genetic algorithm.Based on the CST,the parameter-ization of the geometry of the wind wing is completed by using the 7th-order Bernstein polynomial,the Kriging model is established to greatly shorten the optimization time,and the optimization efficiency and model fitting accuracy are improved by combining LHS and EI plus dots.Comparing and analyzing the opti-mized airfoil with the vertical axis wind turbine NACA0015,the results show that under the designed state,the lift coefficients of the optimized airfoil are increased by 7.81%and 4.42%,the tangential force co-efficients are increased by 10.82%and 6.00%,respectively,and the drag coefficients satisfy the requirement of the constraint conditions.
The fractured vuggy carbonate reservoir of Yijianfang formation in Yueman block of northern Tarim Basin is affected by both structure and karst.Different reservoir sizes and shapes differ greatly,and the reservoir heterogeneity is strong.Therefore,it is of great significance for the exploration and develop-ment of the study area to accurately describe the shape of reservoirs and the distribution of reservoirs in the study area.Based on the understanding of reservoir characteristics and vertical development law of reser-voir,combined with seismic,logging and other data,the reservoir modeling of the study area is carried out based on the overall modeling idea of multi-scale and multi type.For the karst cave reservoir,the sensitive characteristic attribute to the karst response is optimized,the cut-off value is obtained through analysis,the training image is established based on the characteristic attribute,and the modeling is carried out with the well seismic data as the hard data and the cave development probability body as the soft data constraint.Through manual interpretation of seismic data,a large-scale fracture model is established,and ant tracking technology is used for deterministic modeling of medium-scale fractures.For small-scale fractures,density fitting function is used,and ant body is used for random modeling.By fusing multiple models with assign-ment of apposition conditions method,the three-dimensional geological model of fracture vuggy carbonate reservoir in Yijianfang formation of Yueman block is established.
The load-shedding culvert reduces the earth pressure at the top of the culvert by changing the load transfer path of the fill.However,under the long-term load,the EPS plate in the fill and the load-shed-ding hole will creep with time,the stress mechanism of the culvert will change,and the theoretical calcula-tion method of earth pressure under the long-term load is also unknown.In order to explore the theoretical calculation method of earth pressure under short-term and long-term load,the mechanical mechanism mod-el of the load-shedding culvert was established when only two soil columns formed above the load-reducing hole and the culvert side were considered,and the calculation formula of earth pressure on the culvert top under short-term load was derived.Then,considering the creep effect of soil and EPS plate,the calculation methods of culvert top earth pressure under three cases of soil creep,EPS plate creep and soil and EPS plate both creep are deduced.The calculation results are compared with the numerical simulation results,and the correctness of the theoretical formula is verified.
Taking the five-span continuous rigid-frame bridge with high and low piers with the span of(82.5+220+290+220+82.5)m as the research object,the finite element software is used to simulate and analyze its stress and deformation in this essay.The analysis results show that by changing the height difference of the middle pier,the span is symmetrical and the pier height varies.Under the premise that the load on the main beam remains unchanged and under the action of the temperature load,the pier height difference of this bridge should be controlled within 30～40 m.At this time it is conducive to the deformation control and force distribution of the bridge.When the location of the bridge not meet the height difference demand,other relevant measures should be taken to make the bridge force distribution reasonably.The analysis and calculation results could provide reference for the design and construction of other similar bridges.
In order to study the stability and reliability of the normal operation of the vertical axis wind turbine,taking the 1.5 MW vertical axis wind turbine as the research model,a three-dimensional CFD nu-merical calculation model is established.The fluid structure coupling analysis of the wind turbine model is completed by using Fluent software,and the pressure distribution on the blade surface is obtained.The stat-ic analysis module is used to analyze the structural performance of the blade.Finally,the modal analysis of the wind wheel structure of vertical axis wind turbine is carried out.The results show that the stress at the hole connecting the wind turbine blade and the support frame is the largest,and the maximum stress is 64.04 MPa.The maximum deformation displacement occurs at the tip of both ends of the blade,and the corresponding value is 0.028 mm.The wind turbine mechanism is stable and reliable and will not produce resonance during operation.
A two-stage decision model considering consumer-targeting is constructed to analyze the effect of the strategic consumer behavior on decision.In terms of the consumer behavioral characteristics,three consumer-targeting strategies that refer to the proportions of target strategic ad myopic consumers are proposed.The rational expectation theory is applied to figure out the op-timal pricing and order quantity in each consumer-targeting strategy and how to choose the optimal con-sumer-targeting strategy.The results show that the strategy targeting the strategic consumers and the en-tire myopic consumers is infeasible if the consumer heterogeneity is significant;the more strategic or my-opic consumers are targeted,the lower price will be charged but the excessive discounted and excessive or-der quantities are not product would be less available;high cost in unit order,large fraction of strategic con-sumers and their insignificant consumer heterogeneity help sellers choose strategies that target both high-volume and short-sighted consumers.
In order to solve the problem of the reimbursable royalty payment for the corridors,a fair and reasonable payment model is established by applying Shapley value and asymmetric Nash negotiation.First-ly,the Shapley value is used to calculate the proportion of space,direct burial costs and benefits of the inte-grated corridor.Then the asymmetric Nash negotiation is used to calculate the proportion of reimbursable royalty payments for the corridors pipeline units.Finally the feasibility of the model is verified by compa-ring actual projects and methods.The results show that the combined use of Shapley values and asymmetric Nash negotiation can help to balance the alliance cooperation of the corridor units and the satisfaction of in-dividual limited rationality,also can improve the fairness of the paid royalty payment of the integrated cor-ridor,increase the motivation of the corridor units to join the corridor,and promote the healthy develop-ment of the integrated corridor.
Based on the hourly precipitation data of 91 regional automatic stations and national stations in Xi'an from May to October during 2016－2021,the characteristics of precipitation change in flood season and the temporal and spatial distribution characteristics of short-term heavy precipitation in Xi'an are analyzed in this essay.The results show that:(1)the spatial distribution of precipitation and precipitation frequency mainly shows the characteristics of high in the east and west area,decreasing from south to north in the middle area,while the distribution characteristics of precipitation intensity are almost opposite.Xi'an has the largest precipitation intensity in August,and the largest precipitation and precipitation frequency in September.(2)The precipitation and precipitation frequency show the characteristics of single peak phase diurnal variation from early morning to forenoon.The precipitation intensity shows the diurnal variation characteristics of double peak phase at night and in the morning.The correlation between precipitation peak and precipitation frequency is higher.(3)Lintong,the main urban areas of Xi'an,Huyi and Zhouzhi have relatively consistent peak phases of precipitation and precipitation frequency,and the peak precipitation mainly comes from the contribution of precipitation frequency.The precipitation of Yanliang and Gaoling is consistent with the peak value of rainfall intensity,and the peak value of precipitation mainly comes from the contribution of rainfall intensity.The peak phase of rain intensity at stations in Yanliang,Gaoling and Lintong in the northern region basically occurs from night to early morning,and the number is significantly more than that in the southern districts and counties.(4)Lantian,the eastern part of Lintong,Huyi and other places have more short-term heavy rainfall,while Zhouzhi,Chang'an,the main urban area of Xi'an,Gaoling and Yanliang are less.The short-term heavy rainfall in Xi'an mainly occurs from July to August,especially from late July to early August.14:00 to 22:00 and 05:00 to 06:00 are the active periods of short-term heavy rainfall at day time,of which 20:00 to 22:00 and 06:00 are the periods of high occurrence of short-term heavy rainfall,and the maximum rainfall intensity reaches 97.8 mm/h.
The Jurassic Yan 9 and Yan 10 layers are the main oil producing layers in the Wuqi-Dingbian ar-ea,but the development effect failed to meet the expected level due to the lack of understanding of the res-ervoir characteristics.The purpose of this essay tries to provide the geological basis for the oilfield adjustment and development scheme,and to discuss the reservoir characteristics of the Jurassic Yan 9-Yan 10 and the main control factors of the main oil layer and subgroup in the research area.The results shows that Yan 9 and Yan 10 are characterized by medium-low,low-extra low permeabili-ty reservoirs,which mainly develop feldspar quartz sandstone and chip feldspar sandstone.The main contri-bution of them to the sandstone face rate is the remaining intergranular hole and the dissolved pore,and the intercrystalline hole and the microcracks have little effect on improving the physical properties.Compaction and cementing are the main reasons of reservoir compaction,but strong compaction and dissolution are also the main diagenesis of medium-high pore and seepage oil-rich sand belt.
Monitoring and extracting urban built-up areas can identify problems in urban development and provide guidance for future urban planning.In this paper,an object-oriented method for image segmentation was used to extract the built-up areas of the main urban area of Xianyang City based on Landsat ETM+/OLI remote sensing images in 2000,2004,2009,2014 and 2019,respectively.The spatio-temporal expan-sion characteristics of study areas were analyzed using expansion speed,expansion intensity,intensity,frac-tal dimension and compactness index.The results were that the built-up areas of Xianyang City increased by 244.14 km2 from 2000 to 2019,being about 5 times larger than that in 2000.Both the mean annual expan-sion speed(10.28 km2/a)and the expansion intensity(21.11%)showed a rapid expansion trend.The bulit-up areas mainly expanded westward with the main unban area as the center.The mean fractal dimension and compactness index were 1.50 and 0.28,respectively,which indicating that the regularity and compact-ness of urban expansion need to be improved.The expansion of built-up areas was affected by driving forces such as geographic location,economic development,demographic changes,traffic conditions,and policy ori-entation.
Based on the repeated crossing of long pile foundation groups by line 5 of Fuzhou metro shield tunnel,this paper analyzes the structural internal forces and deformation characteristics of the pile founda-tion groups after the shield tunnel is crossed by three-dimensional numerical simulation methods,and fur-ther studies the influence of different ground loss ratios on the force and deformation of pile foundation groups.The results show that the pile foundation under the bridge can reduce the settlement range and set-tlement degree of the surface.The deformation and force of the pile foundation are mainly affected by the burial depth and the spacing between the pile tunnel.Moreover,the greater the ground loss ratio,the grea-ter the difference between the maximum horizontal displacement of the pile foundation and the vertical dis-placement at both ends of the pile foundation and the greater the maximum axial force and bending mo-ment of the pile foundation.When the ground loss ratio is in the certain range,the maximum horizontal displacement of the pile foundation increases by about 1 mm for every 0.1%of the ground loss ratio,the maximum bending moment of the pile foundation increases by approximately 93 kN·m.Therefore,it could provide references for other similar projects.
Based on the analysis of the meteorological background data of Lanzhou International Marathon,an analytic hierarchy process model and the indicators of risk tolerance and control ability were designed according to the characteristics of marathon events.Following the analytic process of risk identification,risk analysis,risk tolerance and control ability analysis and comprehensive risk assessment,a case study was carried out on the application of risk assessment methods for high-impact weather and meteorological disasters in Lanzhou International Marathon.The moderate and high-risk weather affecting the event were determined using the risk matrix method.According to the analytic hierar-chy process model combined with expert scoring,the risk tolerance and control ability was quantitatively analyzed,and the discrimination matrix was constructed to calculate the risk tolerance and control ability of high-impact weather and meteorological disasters.After revising the risk index,the comprehensive assess-ment conclusion was obtained that for high temperature,heavy rain(rainstorm),sand storm and other high-impact weather and meteorological disasters with high risk,weak risk tolerance and control ability that affect Lanzhou International Marathon,measures should be taken for prevention and response.
Carbonate fault-karst reservoir has various reservoir spaces,different scales,strong heterogenei-ty and complex connectivity in Yueman block of Halahatang oilfield in northern Tarim Basin,which seri-ously restricts the efficient development of the reservoirs.In this study,the fault-karst reservoir is divided into large scale fractures,caves,fractures and vugs,which is identified and characterized by using core,drill-ing logging,logging data,seismic data.On the basis of determining the distribution of reservoirs based on 3 D geological modeling,dynamic data is used to qualitatively analyze the connectivity of fault-karst reser-voir,and fault-karst reservoir connectivity is divided into four types:fault connectivity,cave connectivity controlled by fault,vug-fracture connectivity controlled by fault and isolated cave.Finally,the dynamic time warping(DTW)method is used to quantitatively evaluate the connectivity of production wells,and the connectivity evaluation results of DTW method are consistent with static and dynamic data.
Science and technology innovation can promote economic development and ecological protection and is also an important force for realizing the national strategy for the Yellow River basin.Based on the panel data of 79 prefecture-level cities along the Yellow River from 2010-2019,this paper constructs its ecological economic development index and dynamic panel model to explore the impact of science and tech-nology innovation on ecological economy and the regional differences to further explore the intermediate role of industrial structure and green technology innovation as well as the effect of environmental regula-tions.The results show that science and technology innovation can significantly promote the development of the ecological economy in the Yellow River basin,and the effect shows a decreasing trend from down-stream,midstream to upstream and the positive effect on the upstream region is not significant.The inter-mediate effect analysis reveals that science and technology innovation can indirectly facilitate the develop-ment of ecological economy in the Yellow River basin through industrial structure upgrading and green technology innovation.Environmental regulation can play a role,i.e.,environmental regulation can force en-terprises to transform,upgrade and reduce pollution so that innovation can further promote the develop-ment of ecological economy in the Yellow River basin.Finally,based on the above findings,this paper pro-poses four policies and suggestions for ecological protection and high-quality development in the Yellow River basin.
In order to explore the characteristics and variation trend of water and sediment in semi-arid loess re-gion,based on Mann-Kendall non-parametric test,the change trends and mutabilities of precipitation,runoff and sediment in Zuli River basin from 2001 to 2016 were analyzed.The results showed that the annual precipitation did not increase significantly during the study period,the annual variation was 1.83 mm/a,precipitation in flood period showed a decreasing trend,the annual variation was －2.01 mm/a.The curves of annual runoff and flood period runoff presented a trend that dropped significantly(P＜0.05),which were basically consistent.The annual variation of annual runoff and flood period runoff were －3.85×106 m3/a and －2.729×106 m3/a,respectively.The muta-tion time of them was around 2013,and the value of UFkexceeded the 95%reliability line(α=0.05),then it showed a sharp decrease trend.A similar trend of significant reduction was presented between the discharge of sedi-ment and runoff,the variation curves of annual sediment and sediment in flood period were basically consistent,the variation of them are both 1.06×106 t/a,both of mutation time appeared between 2011 and 2012,the value of UFk exceeded the 95%reliability line(α=0.05)after 2014,which showed a sharp decline trend.
Aiming at the BIM modeling problem of rounded rectangular components based on point cloud,a distributed optimization parametric reconstruction method is proposed in this study.Firstly,the PCA a-nalysis was applied on the rounded rectangular beam and column members to reduce to a two-dimensional problem,and the line and rounded curve boundary point clouds of the rounded member were extracted from the plane respectively.Considering the orthogonal and parallel relationship of the straight line boundary,the minimum constraint square method optimization was adopted to get the straight line boundary parameters.Then,the rounded boundary point cloud was transformed by the coordinates to obtain the complete round-ed boundary.Furthermore,the direct least squares method was employed to fit the rounded parameters.Finally the IFC standard 3 D model components were generated based on the estimated parameters.The calculation example showed that this method with high reconstruction ac-curacy was simple in modeling and solution,and could meet the geometrical consistency conditions of com-ponents.
The secondary consolidation deformation of soft soil is an important reason for the slow settle-ment of building facilities.In order to study the secondary consolidation characteristics and evolution rules of the soft soil in Wuhan,multi-group one-dimensional secondary consolidation tests were carried out by applying the graded loading method of the original soil in this area,and the influence of load and over-con-solidation ratio on the secondary consolidation characteristics of the soft soil in this area was analyzed.Nor-malization treatment,curve filting and other methods were adopted to study the deformation law of the secondary consolidation.The test results show that the consolidation coefficient Caincreases step by step with the load increase first and then decrease.Careaches peak near the pressure of the early consolidation,and the natural structure of the specimen is destroyed.The larger the over-consolidation ratio,the smaller the secondary consolidation coefficient.Moreover,affected by the structural changes of the sample,the pri-mary and secondary consolidation boundary points are different under different grades of pressurized load.The ratio of Caand compression index Ccis a certain value before and after the natural structural failure of the sample.By Power and Allometricl,the power function-hyperbolic model related parameters were select-ed.The results show that the model can better reflect the deformation process of the sample when the load is more than 100 kPa.
A multi-model bayes probabilistic decision fusion method is proposed to address the problem of weak generalization ability when using a single deep network to extract different types of water bodies.Three different deep networks U-net,ResUnet and Deeplab v3+are selected as the base classifiers for training and outputting the class probabilities of water bodies which belonging to each pixel on the remote sensing images,and the final water body extraction results are obtained by constructing a probabilistic a-daptive fusion module based on bayes.The experimental results show that the proposed multi-model bayes probabilistic decision fusion method achieves 94.21%of the precision,95.49%of the recall rate and 94.85%of F1 value on the water body test set,respectively.The fusion results for different types of water bodies are more accurate than the averaging method and majority voting method.
Research results and understanding of interlayers in clastic reservoirs are of great significance to the deep tapping potential and sustainable development of remaining oil in old oilfields after years of ex-ploitation.In this paper,Lamadian oilfield formation Sa Ⅱ is taken as an example,based on the principle of reservoir architecture analysis,lithology-physical property analysis and logging identification methods,the genetic types,development characteristics,logging identification criteria and distribution characteristics of interlayers are deeply analyzed.The study shows that:(1)According to the principle of reservoir configura-tion,The interlayer within the SaⅡ formation can be divided into three layers:interlayer between sublay-ers,interlayer between single sandbodies and interlayer in single sandbody,and can be further divided into the muddy interlayer,physical property interlayer and calcareous interlayer from the perspective of compo-sitional origin;(2)The sensitivity logging curves of different types of barriers and interlayers are opti-mized,and the qualitative and quantitative identification criteria of three types of genetic interlayers are es-tablished;(3)The interlayer between(or within)the single sand body of the Sa Ⅱ formation is relatively developed,the corresponding relationship between frequency and density is good,and the heterogeneity within the layer is strong.The interlayer distribution frequency is between 0.364 layer/m and 0.754 layer/m,and the interlayer distribution density is between 0.067 m/m and 0.137 m/m;(4)Small in-terlayers have strong tracking and continuity,large thickness and good oil and gas blocking effect,and the interlayers between single sand bodies are only distributed continuously in a small range.It plays a role in blocking local fluid.Interlayers in single sand body are distributed sporadically.The thickness is the thin-nest,and the ability to seal off oil and gas limited.Therefore,it would provide a certain geological basis for the deep development of Saertu oilfield and tapping the potential of remaining oil.
