摘要:系统可靠性理论与方法是近年来系统工程与管理科学领域的一个研究热点,而工程项目管理领域的系统可靠性及其应用研究尚处于开始探索阶段.基于工程项目管理的目标体系,提出了工程项目施工系统可靠性的概念,界定其内涵为工程项目的质量可达性、成本经济性、资源均衡性、工期合理性和施工安全性的总和.根据工程项目施工系统组合性和层次性的特点,构建了施工系统可靠性计算的金字塔模型,运用不交化最小路集法计算工程项目施工系统的可靠性,并给出了系统可靠性计算的符号表达式.最后,工程实例验证了该方法的有效性.为工程项目施工系统可靠性理论与方法研究做了有益的尝试.%System reliability theory is becoming a focus of international management science and system engineering research, though specific studies are still at a starting stage in the field of construction project management. According to objective system of engineering project, the connotation of construction system reliability is defined that it is the sum of quality attainability, cost economies, resource equilibrium, working time credibility and construction safety of engineering project. Based on the hierarchy and composability of project construction system, a pyramid model is built. Based on the principle of network reliability, a method of disjointed minimal paths set is proposed and the symbol expression formula is given to calculate construction system reliability. This method proved efficient and accurate by an example and it's a useful try on theory and method research of engineering project system reliability.
摘要:掺MgO的RCC混凝土主要运用提高混凝土的防裂特性.通过外掺氧化镁碾压混凝土的特性试验研究,通过弹性模量与自生体积变形的试验,确定本文中碾压混凝土中恰当的MgO掺量为5.5%,并对马堵山大坝碾压混凝土的最大浇筑块的高温环境施工进行精确的温度场和应力场仿真计算,结果表明采用外掺氧化镁技术与埋设HDPE冷却水管相结合的措施对RCC高温施工的防裂是行之有效的温控防裂方法,为随后进行的马堵山碾压混凝土大坝高温环境的施工方案提供了重要的科学依据.%The addition of MgO to concrete proved to be an effective way to improving the crack-preventing properties of concrete . In this work, the optimal MgO content (5.5wt%) is obtained via investigating the addition of MgO on the modulus and autogenous growth of concrete carefully. Combining with temperature controlling units embedded inside the dam, concrete with optimized MgO content was applied in the construction of Madushan Dam under high temperatures. The temperature and stress field were monitored and simulated. The results showed that the addition of MgO combined with internal temperature controlling units could effectively reduce the maximum temperature, the temperature gap inside and outside as well as the maximum internal stress, which is well known for favoring the crack preventing in concrete curing under high temperatures.
摘要:采用光学显微镜(DM)、x-射线衍射(XRD)及拉曼光谱研究了彩色显像管成型锥的显微结构及其抗玻璃液的侵蚀性.结果分析表明:该成型锥属多相非均一结构,有利于提高材料的高温力学性能,在高温下成型锥中的莫来石相与显像管玻璃熔体中的PbO、SrO、K2O、Na2O等组分反应生成物,在成型锥的使用温度下多为高粘度,高温稳定相,同时由于"饱和状态"降低了玻璃熔体对成型锥的进一步侵蚀.%The microstructure and glass melt corrosion resistance of color picture tube forming cone were investigated by means of optical microscope, x-ray diffraction and Raman spectrometer. The experimental results indicate that this forming cone has multi-phase heterogeneously structure, which helps improve the high temperature mechanical properties, at high temperature, the production of reaction between mullite in forming cone and PbO、SrO、K2O、 Na2O which came from glass melt are with high viscos, and with high temperature stable phase. Meanwhile the hyper saturated state is of benefit to glass melt corrosion resistance of forming cone.
摘要:采用梯度设计思想,利用宽带激光熔覆技术,在TC4合金表面分别熔覆Ca/P为1.4和1.5的CaHPO4·2H2O+Caco3混合粉末制备含羟基磷灰石[Ca10(PO4)6(OH)2,简称HA]、β-磷酸三钙[β-Ca3(PO4)2,简称β-TCP]的度生物陶瓷涂层.采用XRD、SEM等表征手段,研究不同Ca/P粉末配比对生物陶瓷涂层组织结构的影响.研究表明:由于P在激光条件下存在烧损现象,当Ca/P为1.5的粉末经激光熔覆后所生成的陶瓷组织较Ca/P较1.4结晶状态更好.不同Ca/P粉末以及CeO2的添加量对催化合成HA+β-TCP有着深刻的影响.当Ca/P=1.4,CeO2的添加量为0.4wt%时,催化合成HA+B-TCP的数量最多;而当Ca/P=1.5,CeO2的添加量在0.2~0.4wt%范围内,催化合成HA+β-TCP的量最多.%In the present paper, the use of the gradient design and the wide-band laser cladding technology , on the surface of the TC4 alloy, the powder of CaHPO4 · 2H2O+CaCO3 whose Ca/P is 1.4 and 1.5, was mixed to prepare the gradient bioceramic coating with hydroxyapatite Ca 10 ( PO4 ) 6 (OH) 2 (HA), β- tricalcium phosphate β- TCP [β- Ca3 ( PO4 ) 2 ].With the aid of scanning electron microscope (SEM) ,X-ray diffraction (XRD) and other analysis, different Ca/P effected on the bioceraic coating microstrueture was studied. Result shows: because the phosphor (P) is burned under the condition of the laser, when Ca/P is 1.5, the ceramic structure after laser cladding has better crystalline state than the ratio 1.4 of Ca/P. Different Ca/P powder and CeO2 contents have significant impact on synthesizing HA+β-TCP. When Ca/P is 1.4 and the addition of CeO2 reaches 0.4wt%, the synthesizing HA + β-TCP is the greatest amount; and when Ca/P is 1.5 and the content of CeO2 is between 0.2wt% and 0.4wt%, the synthesizing HA + β-TCP is the greatest amount.
摘要:在温度高达840℃,固气比高达2.54的条件下,对旋风预热器总分离效率进行了实验,研究了温度、固气比和风速对旋风预热器总分离效率的影响,根据实验数据回归分析,得到了回归方程.填补了高温高固气比条件下旋风预热器总分离效率研究的空白.%As temperature going up to 840℃ and solid-gas mass ratio to 2.54, the author has measured the overall efficiency of cyclone preheater, discussed the influnces of temperature,gas velocity and solid-gas mass ratio to the overall efficiency, and obtained regression equation according to experimental data analysis and filled the gap in the investigation into overall efficiency of cyclone preheater in condition of high temperature and high solid-gas mass ratio.
摘要:首先对1株新疆杨进行了阻风效应试验,得出了新疆杨对降低风速及风压的效应很明显的结论;然后通过对5株新疆杨进行实验室条件下的模拟自然风的动力加载试验,得出了新疆杨的风致动态位移及风致动态应变特征曲线;其次通过对4株新疆杨进行野外真实风条件下动力加载试验,得到了风致动态应变、风致动态位移、风致动态速度及风致动态加速度响应特征曲线;最后对室内和野外两种试验条件下的新疆杨动态响应特征曲线进行了对比.试验及分析表明:新疆杨树干上同一方向的上、下两测点位置的位移、速度及加速度具有明显相关性;在随机风荷载激励下,林木的外表层纤维交替处于拉压状态;随着林木高度的增加,林木的风致动态位移越大.本文对林木防风减灾及林木保护具有重要的理论意义和实用价值.%Firstly, the wind-resistance effect test was carried out with one P. bolleana in this article, and a conclusion was arrived at that P. bolleana was obviously effective to reduce wind speed and wind pressure. And then through dynamic loading test of five P. bolleana under laboratory condition simulating natural wind power, the characteristic curves of wind-induced dynamic displacement and wind-induced dynamic strain were acquired. In the dynamic loading test of four P.bolleana under the condition of true wind power outdoors, characteristics curves of wind-induced dynamic strain, wind-induced dynamic displacement, wind-induced dynamic speed and wind-induced dynamic acceleration response were also obtained. Finally, a comparison was carried out on the dynamic response characteristic curves of P. bolleana under both indoor and field test conditions. Test and analysis showed that displacement, velocity and acceleration had obvious pertinence on the upper and lower measuring point position in the same direction of stem of P. bolleana, and in the random wind load excitation, the forest fibers of outer surface were in alternating tension-compression state, and with the increase in forest height, wind-induced dynamic displacement of forest was larger. This article has the important theorelical significance and practical value to wind resistance, disaster alleviation and protection of forest.
摘要:In view of the evaluation of environmental influence , based on the analysis of quality on highway landscape in China and the confusing content of evaluation, there is no uniform, normative and feasible method for quantitative evaluation. Through investigation, research, and practice of a large number of environmental highway landscape, the research method can be used for our reference landscape ecology. To explore the on landscape environment along the highway,this paper analyzd landscape spatial pattern in small scale, chose some index systems such as the number patches, size and scale of landscape spatial pattern ,the landscape crake index and landscape richness index to evaluate highway landscape environment quantitatively. Meanwhile, the paper used an evaluation index system, drew the support from ArcGis9.2 (geographical information system)and Fragstats3.0(The landscape pattern analysis software) in calculating , evaluating and analyzing the index of feature on the spatial pattern tourist highway landscape of Shen Nong-jia.%针对我国公路景观环境影响评价多以定性分析为主,评价内容庞杂无序,目前尚无统一、规范、切实可行的定量评价方法.通过对我国大量公路景观环境的调查、研究、探析与实践,借鉴景观生态学研究方法,探索在公路沿线景观环境研究范围内,从小尺度上分析景观空间格局,提出选取反映景观空间格局的斑块数量、大小、形状及景观破碎度、景观多样性等指标体系对公路景观环境进行定量评价.并采用该评价指标体系,借助地理信息系统ArcGis9.2及景观格局分析软件Fragstats3.0,对神农架旅游公路景观空间格局特征指标进行计算、评价与分析.
摘要:钢框架结构在强烈地震荷载作用下,传统的栓焊连接(或全焊连接)节点表现出大量的脆性破坏,迫使人们重新认识钢结构的抗震性能,并探究具有良好抗震性能的梁柱刚性连接形式.本文考虑了对梁柱连接局部加强的方法来提高节点承载力和转移塑性铰位置的几种连接形式,通过低周反复荷载试验进行了验证.发现这种加强型梁柱连接虽然在地震荷载作用下对承载力的提高并不明显,但可以保证有效地将塑性铰外移,大大提高节点的延性,从而加强了节点的耗能能力,达到避免节点脆性破坏的目的.在此基础上,对加强型梁柱连接在地震荷载作用下的内力传递、变形发展和塑性铰外移的过程进行了深入的理论分析,揭示了加强型梁柱连接的抗震工作机理.%Under intense seicmic loading, brittle failure usually occurs in steel moment-resisting frames with traditional bolt-welded connections or full-welded connections.Then people are forced to be aware of the seismic performance of steel structures.And new forms of rigid beam-column connections with good seismic behavior have to be explored.In this paper, several kinds of beam-column connections with local reinforcement are employed to improve the bearing capacity of nodes and transfer the location of plastic hinges, which have been verified through low-cyclic reversed loading test.It is shown that although the increase of the bearing capacity of the reinforced beam-column connection is not obvious under seismic loading,it is sure that the plastic hinge can be effectively relocated and the ductility of the node can be greatly enhanced.Therefore, energy dissipation capability of the node can be improved, and brittle failure can be avoided in the node.Based on test results, further theoretical analysis of internal forces transmission, deformation development and the process of outward relocation of plastic hinge of the reinforced beam-column connections under seismic loading are carried out and the aseismic mechanism of reinforced beam-column connections is revealed.
摘要:自适应序贯非线性最小二乘法是一种新型的损伤识别方法.为了减少结构中传感器的数量,将有限元模型缩聚理论与自适应序贯非线性最小二乘法相结合,用于结构的损伤识别--基于缩聚模型的自适应序贯非线性最小二乘法.为了验证该方法的有效性,对一悬臂梁结构进行了试验研究,研究中考虑了白噪声、正弦、和EL-Centro地震波三种激励下的六种工况.研究结果表明,基于缩聚模型的自适应序贯非线性最小二乘法是一种有效的结构损伤识别方法,根据该方法,只需要使用少量的传感器即可准确地识别出结构中损伤的发生时刻、损伤的程度和位置.%Adaptive sequential nonlinear least-square estimation approach is a new structural damage identification technique. In order to reduce the number of sensors in structure health monitoring system, a reduced-order finite-element approach along with the adaptive sequential nonlinear least-square estimation approach is proposed to identify the local damages of complex structures, which is referred to as the reduced-order finite-element model based adaptive sequential nonlinear least-square estimation approach. To verify the capability of the proposed approach, at first a simulation test was performed on a 3-D truss, and three cases under two excitations were considered, including white noise excitation and EL-Centro earthquake excitation. Then experimental tests were performed on a scaled cantilever beam, and six cases under three excitations were considered, including white noise, sinusoidal, and El-Centro excitation. Simulation and experimental tests indicated that the proposed reduced-order finite-element model based sequential nonlinear least-square estimation approach is an effective structural health monitoring method. By using only a few sensors, the structural damages can be detected accurately, including the location and severity of the damage.
摘要:In order to study the seismic performance of corner joint in SRC(steel reinforced concrete) special-shaped column frame, tests were carried out on four specimens under low cyclic reversed loading. It is shown that load-displacement hysteretic curves of corner joint in SRC special-shaped column frame are plump. The joint has good seismic performance.Based on the experimental reasearch, finite element analysis software ABAQUS was used to simulate the properties of specimens and the calculating results proued consistent with those of the test. Further more, the factors affecting the shear capacity of specimens have been reasearched. Results show that the shear capacity of specimens increases with the axial compression ratio in certain extent and the steel ratio in core zone of the joint. The increase of shear capacity of the specimen with lower axial compression ratio is larger than the specimen with higher axial compression ratio. The position of horizontal load point has a minor effect on the shear capacity of specimens.%为了研究型钢混凝土异形柱框架角节点的抗震性能,进行了四个模型试件的低周反复荷载试验.结果表明,型钢混凝土异形柱框架角节点的滞回曲线饱满,抗震性能良好.在试验研究的基础上,通过有限元软件ABAQUS对试件进行了模拟分析,并与试验结果进行对比.二者符合较好.进而对承载力的影响因素进行了分析.结果表明:在一定范围内,轴向压力能提高试件的抗剪承载力;随着配钢率的增大,试件的抗剪承载力逐渐增大,在轴压比较小时,抗剪承载力增幅较大,当轴压比较大时,抗剪承载力增幅较小;水平荷载合力作用点的位置对试件的抗剪承载力影响较小.
摘要:Based on the strain rate enhancement factor, damage weakening factor and pre-stressed enhancement factor, this paper has analyzed their impact on the strength of pre-stressed concrete and established a uniaxial tensile dynamic constitutive model which is used to describe the impact properties of PHC piles under impact load.The model simulation results were compared with the experimental results, which shows that the results indicated by this model is good agreement with the deformation trend and agreement with the experimental results in numerical accuracy.The results of this paper can provide the basis for controlling the vibration parameters in the process of vibrating pile.%通过引入应变率强化因子、损伤弱化因子和预应力强化因子,并分析它们对预应力混凝土强度的影响,建立了一个单轴受拉动态水构模型用于描述PHC桩在冲击载荷作用下的冲击特性.对比了试验结果与该模型的数值模拟结果,结果表明:模型预示结果在变形趋势上符合很好,在数值精度上与试验结果符合良好.本成果可为振动沉桩过程中控制振动锤参数提供依据,能有效防止因拉应力过大而导致PHC桩被拉断的事故.
摘要:外循环式分解炉是一种新型的反应器,主要用于新型干法水泥生产工艺.理论计算表明该炉型具有更稳定的热工性能和更高的出炉物料表观分解率.采用带旋流修正的k-ε双方程模型对外循环式分解炉内的气相湍流流场进行了数值模拟.分析了该分解炉内的气流流线特征和不同截面的压力分布和气流速度情况.结果表明:受三次风偏心进入的作用,气流在分解炉下部形成较为强烈的返混和旋流效应,进入分解炉上部后趋于稳定.流体进入旋流分离器后,形成稳定的下行旋转流动,接近出口时,受流动空间缩小的影响,流体加速流出分解炉.以上结果验证了该分解炉设计合理,为煤粉在炉内的燃烧、碳酸盐的分解提供了较好的流场.%External circulating precalciner is a new type of reactor, which is mainly applied to the new dry process for the cement manufacture. Theoretical calculation indicates that the external circulating precalciner possess more stability of thermal performance and higher apparent resolution rate of the discharge material. The numerical simulation of the gas flow field in the external circulating precalciner based on the RNG k-ε model is introduced. The characteristics of the gas flow stream line in the precalciner and the distribution of the pressure and gas velocity with different parts were analyzed.The results indicated that a relatively strong back mixing and rotational flow field formed in the under-part by the effect of the tertiary air partiality into precalciner, and the flow field becomes stable since the gas enters the top of the precalciner.When the fluid flows into the rotational flow separator, the steady downstream spin is formed. Affected by the reduction of flow space close to export, fluid flowing quicken outflow the precalciner. The simulation results verified the precalciner for the pulverized coal burning and the carbonate decomposing was designed reasonably.
摘要:Based on the structure and mathematical model of life cycle total cost in air-conditioning system, the life cycle total cost of a surface water heat pump system in Chongqing is calculated. The results show that the system settings are not reasonable; the LCC is not always the lowest, and sometimes it may be higher than other air-conditioning systems. Only the reasonable scheme can get the lowest LCC. Through analyzing the actual test data, the load characteristic, water supply energy consumption, water supply temperature and other main factors are found that can influence LCC of surface water heat pump. Finally, matters which require attention in obtaining the lowest LCC are pointed out.%利用空调系统的全寿命周期成本(LCC)的构成以及数学计算模型对重庆某地表水源热泵工程的全寿命周期成本进行了计算.结果表明,系统设置不合理,地表水源热泵的LCC值并非是最低的,会高于其他空调系统;而合理的地表水源热泵方案才能够得到最低的LCC值.对实际测试的数据进行了分析,找到了影响地表水源热泵的LCC值的主要因素有负荷特征、取水能耗和取水水温等.最后指出了取得最低的LCC值应注意的问题.
摘要:随着水资源供需矛盾日益加剧,再生水作为替代水源成为缓解水资源紧缺的重要措施.概述了我国的水资源现状、水资源缺乏的原因和因缺水造成的重大损失,阐释了缺水地区将城镇污水开发为稳定水源的概念和特点,并从解决缺水地区水资源供需矛盾、确保生态需水量、严格实施污水治理政策等方面论述了新生水源开发的意义,提出了新生水源水法规政策的制定、标准的建立和处理技术的研究是目前亟需解决的几个科学问题.%Water scarcity has been growing with the increment of municipal water supply and groundwater quantity deterioration. As a means to alleviate water deficency reclaimed water has been used widely world-wide. In this paper, the water resources of China, causes of water scarcity and the losses caused by water scarcity were analyzed. The reclaimed water can be taken as a stable resource in water deficient regions. It can play an important role in resolving the water scarcity,satisfying ecological water requirement in carrying out the policy of wastewater treatment. Finally, several challenges for people to meet are briefly described.
摘要:建立了一种活性炭超声萃取-毛细管柱气相色谱联用的方法,对水中痕量丙烯酰胺进行定量分析.通过对乙酸乙酯液液萃取,Agilent ODS-C18固相萃取柱(500 mg,6 mL)萃取以及活性炭超声萃取这三种方法进行了比较与优化,实验结果表明活性炭超声萃取方法对大体积水样的萃取效果最佳,并通过精密度,重现性和加标回收率等实验得到了论证.该方法最低检测限达到0.05/μg/mL,灵敏度高,重现性好,适用于痕量丙烯酰胺的分析.%An ultrasonic extraction of activated carbon-capillary gas chromatography method is established for the determination of trace acrylamide in water by comparing and optimizing ethyl acetate liquid-liquid extraction, agilent ODS-C18 solid phase extraction column (500 mg, 6 mL) extraction with ultrasonic extraction of activated carbon. The results showed that ultrasonic extraction of activated carbon was the best for extraction of water samples generally, which was demonstrated through the precision, reproducibility and recovery experiments. The detection limit of the method was 0. 05 μg/mL.This method is desirable for high sensitivity and good reproducibility, and it can be applied to determine the trace acrylamide.
摘要:坚固是一座建筑存在的根本,也是使用者安全问题的保证.先进结构技术构成了推动建筑快速发展的主导力量.通过预应力技术改变石构件截面上的应力分布、状态和性质,使其满足规范规定的各项安全标准,并使石材的冷脆性得到一些弹塑性改善,从而拓宽石材的应用范围.同时将预应力技术与传统榫卯技术相结合,解决了石材作为建筑材料不能用于大跨度承重构件的难题,为此类项目的实施提供了理论依据.%Solidity is not only essential to an architecture existing.It is also the user's safe guarantees.The advanced structure technology constituted the dominant force promoting the rapid development of construction engineering.By changing the stress distribution, state and property of stone component cross-section through the pre-stressed technique so as to meet the specification of the safety standards, and improving the stone cold brittleness so as to broaden the scope of application of stone.Meanwhile, by combining the pre-stress technique and the traditional mortise and tenon technique, problem that the stone as a building material can not be used in the large-span load-bearing component is overcome and this, it can provide a theoretical basis for the implementation of such projects.
摘要:This paper introduces the construction technology of mass concrete foundation of large scale shaking table in Laboratory of Structure Engineering on the new campus of Xi’an University of Architecture and Technology. In order to effectively control the temperature deformation and cracks in mass concrete construction,according to the mix proportion design, using low hydration heat cement, well-graded aggregate and proper admixture can strictly control the use of raw materials. Technical quality control measures, such effective and reasonable construction technology and method as concrete pouring, temperature measure, insulation, and concrete curing in later period, can ensure the quality and safety of foundation works. As a result, temperature deformation cracks no longer appear. It has been proved by practice that these measures of preventing cracks are effective.%介绍和论述了西安建筑科技大学新校区结构实验室大型模拟振动台基础大体积混凝土施工技术,为了有效控制大体积混凝土施工时出现温度变形和开裂问题,按照配合比设计采取低水化热水泥、级配良好的砂石和合理的掺合料等严格控制好原材料的使用,施工时采用有效合理的混凝土浇筑施工工艺、方法和后期测温保温养护等技术质量控制措施,确保了基础工程的质量安全,未出现温度变形裂缝,实际工程应用证明,这些防止裂缝措施是非常有效的.
摘要:According to the character under power of curved continuous rigid frame bridge with high pier from single pier,cantilever construction to complete bridge, the equivalent restraint stiffness spring is utilized to simplify the main beam constraint to the main pier in the state of completed bridge. The dynamic stability equations of structures at each stage are derived by Hamilton principle and are converted in to the static stability equations. Based on these, the static stability factors of structures are obtained and the effect of various parameters to the stability of curved continuous rigid frame bridge with high pier is studied here. The purpose of the paper is to seek a practical simple stability analysis arithmetic of long span curved continuous rigid frame bridge with high pier. Through the case study to verify the calculation results a certain reliability is providcd.%根据高墩弯连续刚构桥从裸墩、悬臂浇筑施工到成桥各阶段的受力特点,将成桥后主梁对主墩的约束作用简化为等效约束刚度的弹簧,利用Hamilton原理,推导高墩自体、悬浇施工以及成桥阶段的动力稳定方程,进一步退化为静力稳定问题,得到了静力稳定系数表达式,并分析了诸因素对高墩弯连续刚构桥稳定性的影响.从而寻求高墩大跨弯连续刚构桥梁空间稳定性的实用简便算法.通过实例分析,验证其计算结果的可靠性.
摘要:The holistic classroom building group has appeared for almost 10 years. In order to improve the design quality,a further discussion of its essence was necessary. In this paper, the disadvantages of traditional classroom building on university campus in our country and the appearance background of holistic classroom building group were firstly introduced.Secondly, based on the conception definition, the connotation of holistic classroom building group was analyzed, including the feature of cluster and integration. Finally, by summing up the elements and the corresponding compound modes, the optimized design strategies of the holistic classroom building group have been put forward.%整体化教学楼群在我国高校出现已近10年,需要更深的理解其本质,以进一步提高设计质量.通过说明我国高校传统教学楼存在的弊端以及整体化教学楼群的出现背景,在界定其概念的摹础之上,深入解析了高校整体化教学楼群的概念内涵,即"群"的特性和"整体化".通过总结整体化教学楼群的建构要素及要素组合方式,提出了其建构模式.
摘要:The public space of participatory design is based on the theory of participatory development in anthropology and the theory of Alexander's "Pattern Language". With theoretical innovation and design method of the practice. participatory design can gradually change the original design of top-down model. Efforts are made to enable real user groups to participate in the design of the decision and implementation. Taken as example is Guangzhou urban village community public space design experiments showing how this sort of design pattern may participate in the development of local culture. It makes public space residents' real life ingredient everyday. It also makes public design the spirit carrier serving the public.%公共空间的参与式设计是结合人类学中的参与式发展理论和亚历山大"模式语言"进行理论创新与设计方法实践的一种尝试.参与式设计逐步改变原有的自上而下的设计模式,力求使得空间真正的使用者群体能够参与设计的决策与实施.本文完成的设计项目以城中村社区公共空间设计实验为例,研究参与式的设计模式如何在本土人文背景下衍生、发展.
摘要:According to the similarity between the evolution of industrial cluster and biological population evolution, and the Logistic model in the theory of ecological population evolution, cluster industries of competition and cooperation co-evolution model has been constructed and studied.The research shows that the co-evolution is the motive power of industrial cluster system evolution.During the evolution process, the competitive and cooperative system will finally stabilize the system.%针对产业集群演化与生态种群演化之间的高度相似性,借鉴生态种群演化理论中的Logistic模型,构建了集群产业竞争与合作的协同演化模型,并对模型进行了实证研究.研究结果表明,集群主体间的协同是产业集群系统演化的主要动力.在产业集群系统的演化过程中,集群主体间既竞争又合作的协同机制,推动集群发展演化,并最终实现整个集群系统的稳定.
摘要:To study the mechanical behavior of rectangular hollow section (RHS) steel tube joints with concrete filled in chords, mechanical behavior of compression, tension and bending are analyzed in this paper and compared with RHS steel tube joints. The results show that concrete filled in chord can improve the mechanical behavior of joints. It can obviously enhance the ultimate bearing capacity and rigidity of compression joint, and the failure mode of compression joints is local transverse compression failure. It does not have much effect on the ultimate bearing capacity of tension joints, but can enhance the rigidity of joints; and it can change the range of geometric parameters of failure mode; the failure modes of tension joint are punching failure mode, effective width failure mode and flange yield-line failure mode. The bending rigidity and ultimate bending capacity of joints are greater than RHS steel tube joints, and the failure mode of bending joints is considered as tension flange effective width failure mode of branch tube. The bearing capacity formula for three types joint are recommended according to its failure modes.%为研究主管内填混凝土对矩形钢管节点受力性能的影响,探讨主管内填混凝土矩形钢管节点的受力机理,对比分析了主管内填混凝土矩形钢管节点和空钢管节点的受压、受拉和受弯性能,结果表明主管内填混凝土能够改善节点的受力性能,显著提高矩形钢管受压节点的承载力,受压节点的破坏模式转变为横向局部承压破坏;对矩形钢管受拉节点承载力提高不明显,但提高了节点的刚度,改变节点的破坏模式;能够提高受弯节点的刚度和承载力,其破坏模式可采用支管受拉翼缘有效宽度模型.主管内填混凝土后矩形钢管节点的承载力可根据对应的破坏模式来计算.
摘要:Based on the moving coordinate and the Navier's integral transform solutions, simulating the transit load by double freedom degree system, dynamic equations of train—track—ground system are solved, and the analytical solutions are derived exactly.A comparative and verifiable analysis indicates that the solutions are accurate.The effects of velocity and frequency of the moving load and elastic modulus of soils on dynamic response of system are investigated and compared with viscous-elasticity half-space, which is of significance to the engineering.%采用移动坐标系,用双自由度体系模拟作用于轨道体系的车体荷载,结合粘弹性半空间积分变换解,求出列车--轨道--地基系统动力响应基本解.算例验证表明本文分析方法的正确性,数值分析了荷载移动速度、频率和土体弹性模量对系统动力响应的影响,并与荷载直接作用在地基上时地基土响应作比较,给出对工程实践有意义的结论.
摘要:从信息系统管理的视角出发,构建了能耗监测管理的系统平台,并以西安市工程交易中心为例,对能耗情况进行了统计分析.基于此,研究分析了能耗监测系统的构架体系,从信息管理系统视角提出了未来大型公共建筑物的能耗和节能管理途径和措施,形成了基于信息化管理的建筑节能管理模式.%This paper is based on information system management perspective, designing an energy consumption management system. By taking Xi'an project transaction center as an example, we analyzed its energy consumption. Further, we explored the new mode of energy-saving management-based energy consumption system. This study will provide new perspective and ideas for China country's energy-saving theory and practicce for relative governmental institutions.
摘要:区位可达性的改善使得居民住宅区位选择范围扩大.地铁的兴建不但改善了区位可达性,同时也使得沿线住宅供需情况随之而变.根据城市经济学理论,运用竞租模型探讨了不同收入群体居住用地的分配情况,并分析了区位可达性改善而引发的竞租模型的变化,并推导出竞租模型变化的条件.采用统计列表分析的方法,以西安市地铁2号线开建时间节点前后两年半的145个楼盘数据作为样本进行分析,得到因地铁的兴建,沿线住宅户型产生的变化与分布情况,证实了理论分析的结论.%Location accessibility improvement can make residential location selection scope expand.Building of the metro can not only improve location accessibility, but the changing of the situation of residential supply and demand.According to the urban economics, and by using the bid-rent model, this paper discusses the different income groups of residence land distribution, pointing out that the location accessibility improvement changes the bid-rent model, and deduces the bid-rent model changing conditions.And then by using statistic analysis of 145 flats data of the 2.5 years before and after the building of Xi'an metro line No.2 the paper confirms the conclusion of the theoretical analysis.
摘要:Aimed at the redundancy caused by double counting and the irrationality caused by isolation in the past analysis of multi-factors, in this article, an FNN(fuzzy neural network) model of eco-environmental water demands based on AHP (analytical hierarchy process) under cascade development was put forward. AHP was used to analyse the interaction of risk factors of eco-environmental water demands, to establish quantitative indicators' compound weight on various factors, and, the weight sets were input as initial weight values of the impact factors of FNN model, thus effectively eliminating the impact randomly assigned initial values on the model results, And to the upper reaches of the Yellow River,with Longyangxia as an example, the comparative analysis of model fitting and risk studies were carried out. Project instance application shows that the model built is reasonable and feasible, and has a better fitting accuracy and some practical value for engineering.%针对以往多因子分析中存在因重复计算所致的冗余和因孤立计算所致的结果不合理,提出和建立基于风险因子层次分析法的生态环境需水量模糊神经网络模型;采用层次分析法分析生态环境需水量风险因子间的相互作用,建立其量化指标组合权重关系,并将权重值作为所建FNN模型的初始权值输入,从而有效消除了系统随机赋予初始权值对FNN模型结果的影响,并以黄河上游龙羊峡河段为例,进行模型拟合与风险分析.结果表明,所建模型合理可行,其拟合精度较高,具有较强的工程实用价值.
摘要:20 factors are selected to frame a primary factor set from 38 factors obtained though literature study. The methods of Mean Score and Ranking Agreement Factor are applied to calculate the sorting order and analyze the consistency of market survey data. The results show that 17 factors about owner's engineering capabilities, owner's preferences to project construction, project properties, and lump-sum contracting market conditions exert a profound influence on the decision-making of lump-sum contracting project delivery methods. Finally, countermeasures and suggestions are proposed to promote the rapid and sound development of lump-sum contracting system in the construction industry of China.%通过文献研究总结出的38个总承包成功交易模式决策的重要属性,并从中选出20个作为我国总承包工程交易模式决策的初选属性集;运用Mean Score和Ranking Agreement Factor模型对总承包工程交易模式决策初选属性重要性的市场调查数据进行排序计算和一致性分析.结果显示,来自业主工程技术能力、业主工程建设偏好、项目性质与总承包市场条件4个方面的17项属性对我国总承包工程交易模式决策产生重要影响.最后提出了促进我国建筑业工程总承包制度快速健康发展的对策和建议.
摘要:东岗镇黄河大桥是重要的交通枢纽,对其进行耐久性评估和寿命预测对于确保包兰铁路的正常运营有极其重要的意义.对大桥结构技术状况进行了详细的检测与调查,测试了大桥主要构件混凝土保护层厚度、混凝土强度、及混凝土碳化深度和钢筋锈蚀程度,分析了大桥混凝土结构的主要病害及其产生原因.基于大桥环境条件和主要构件实测结果,分析了大桥主要构件的碳化可靠指标和剩余寿命,为大桥的继续使用与维修加固提供了科学依据.%The Donggang Yellow River Railway Bridge is a transportation hub, and the durability evaluation and life prediction of the bridge is extremely significant for ensuring the normal operation of the railway. The detailed detection and investigation were given to the structurd technical condition of the bridge, the thickness of concrete protective layer, concrete strength, carbonation depth, and the reinforcement corrosion of the main component of the bridge were detected, and the main diseases and their causes of the bridge were analyzed. Based on the environmental conditions and the detection results of the bridge, the carbonation reliability index and residual life prediction of the main component of the bridge were analyzed, and scientific basis was provided to continue using repairing, and reinforcing the bridge.
摘要:为了揭示风化岩填料路基的工程性质,结合室内击实实验与施工段现场沉降观测实验,深入分析了风化岩路基沉降随时间的变化规律,同时,对风化岩填料路基的边坡防护进行了概述.该研究成果可用于指导、评价山区高速公路风化岩路基填筑,这不仅是对保护环境、实施可持续发展战略的双重要求,而且具有较高的经济和社会效益.%In order to reveal the weathered rock subgrade engineering properties of packing, combining with the compaction test and construction of indoor experiment site settlement observation period, in-depth analysis of the rock embankment settlement may chang with time and the weathered rock fill embankment slope protection is also taken into consideration.Therefore this research results can be used to guide mountainous highway roadbed compactness of a weathered rock,which not only benefits environmental protection and sustainable development strategy, but also meats the dual requirement with high economic and social benefits.