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1.
Construction simulation and real-time control for high arch dam 总被引：1，自引：0，他引：1
A method of combining dynamic simulation with real-time control was proposed to fit the randomness and uncertainty in the
high arch dam construction process. The mathematical logic model of high arch dam construction process was established. By
combining dynamic construction simulation with schedule analysis, the process of construction schedule forecasting and analysis
based on dynamic simulation was studied. The process of real-time schedule control was constructed and some measures for dynamic
adjustment and control of construction schedule were provided. A system developed with the method is utilized in a being constructed
hydroelectric project located at the Yellow River in northwest China, which can make the pouring plan of the dam in the next
stage (a month, quarter or year) to guide the practical construction. The application result shows that the system provides
an effective technical support for the construction and management of the dam.
ZHONG Denghua, born in 1963, male, Dr, Prof.
Supported by National Natural Science Foundation of China(No.50539120), National Basic Research Program of China(“973”Program,No.
2007 CB714101), National Science Fund for Distinguished Young Scholars of China(No.50525927), and National Natural Science
Foundation of China (No.50579045). 相似文献
2.
Sequence placement logic plays a significant role in construction simulation of high arch dams and directly affects the simulation process and results. To establish a sequence logic for dam block placement, the construction scheme, real-time construction process, and random factors of the site all need to be considered in detail. There are few studies available currently that take all these factors into consideration. To address this problem, a real-time update of sequence placement logic for high arch dams based on evidence weight discount is proposed in this study. First, the subjective weight of the dam block sequence priority criteria is built using a consistent matrix method based on the construction scheme. Second, using evidence theory, dynamic objective weight of the priority criteria and basic probability assignment is built. Finally, using a weight self-adaptive adjustment method and comprehensive evidence discounting, the placing probabilities of different dam blocks are obtained. A case study indicates that this method can realize real-time update of sequence placement logic. 相似文献
3.
4.
The parameters of existing roller-compacted concrete (RCC) dam construction simulation are usually fixed based on experience while the actual construction conditions of an RCC dam change during the process of the project. The simulation accuracy of an RCC dam is therefore reduced because the change has not been considered. A new method for RCC dam construction simulations based on real-time monitoring is presented in this paper. First, real-time monitoring technology is used to collect and analyze the actual construction information. Second, meteorological data obtained from the real-time monitoring system are analyzed using the fuzzy average function method, and the weather conditions of the next stage are forecasted. Then the construction schedule simulation model is updated via the Bayesian update method. Results of the analysis are used as the input to the construction simulation parameters, and the construction simulation is performed. A real-world engineering example is presented to compare the simulation results with the actual construction schedule. The results demonstrate that the method can effectively improve the accuracy and real-time performance of construction simulations. 相似文献
5.
It is important and difficult to control the temperature of mass concrete structure during high arch dam construction.A new method with decision support system is presented for temperature control and crack prevention.It is a database system with functions of data storage,information inquiry,data analysis,early warning and resource sharing.Monitoring information during construction can be digitized via this system,and the intelligent analysis and dynamic control of concrete temperature can be conducted.This method has been applied in the construction of the Dagangshan Arch Dam in China and has proven to be very convenient.Based on the decision support of this system and the dynamic adjustment of construction measures,the concrete temperature of this project is well-controlled. 相似文献
6.
全寿命费用分析方法以教育装备的全费用为指标,对装备工作进行优化,从而达到节约资金的目的。但是教育装备工作不仅要考虑费用的支出,更应考虑获得的效果。提出代价——效果综合分析方法可更加全面地优化教育装备工作,为教育装备建设决策提供支持。详细介绍了代价——效果综合分析方法的思路、模型和实施案例。 相似文献
7.
An optimal allocation of earth is of great significance to reduce the project cost and duration in the construction of rock-fill dams. The earth allocation is a dynamic system affected by various time-space constraints. Based on previous studies, a new method of optimizing this dynamic system as a static one is presented. In order to build a generalized and flexible model of the problem, some man-made constraints were investigated in building the mathematic model. Linear programming and simplex method are introduced to solve the optimization problem of earth allocation. A case study in a large-scale rock-fill dam construction project is presented to demonstrate the proposed method and its successful application shows the feasibility and effectiveness of the method. 相似文献
8.
Calculation Model of Equivalent Strength for Induced Crack Based on Double-K Fracture Theory and Its Optimizing Setting in RCC Arch Dam 总被引：2，自引：0，他引：2
By means of fracture testing on roller-compacted concrete (RCC) three-point bending beams with two different specimen sizes, the P-CMOD complete curve for RCC was gained. Furthermore, by applying double-K fracture theory, KIC^ini,KIC^un, as well as the critical effective crack length and the critical crack tip opening displacement, were evaluated. Based on the double-K fracture parameters above, the calculation model of equivalent strength for induced crack was established, thus the calculation method on its initiation, stable propagation and unstable fracture was ascertained. Moreover, the finite element simulation analysis of stress field in ShaPai arch dam and the on-site observational splaying points of induced crack at different altitudes validated the reliability of the model. Finally, crack inducer‘s optimal setting in RCC arch dam was studied. It improves the design level of induced crack in RCC arch dam and satisfies the necessity of engineering practice. 相似文献
9.
The quality of compaction is key to the safety of dam construction and operation. However, because of incomplete information about the construction process and the unknown relationship between compaction quality and the factors that influence it, traditional evaluation methods such as neural networks and multivariate linear regression models fail to take uncertainty fully into account. This paper proposes a cloud-fuzzy method for assessing compaction quality by considering randomness, fuzziness, and incomplete information. The compaction parameters and material source parameters are the key parameters in the assessment of compaction quality. A five-layer neural-network model of compaction quality assessment is established that considers compacted dry density and its classification membership and probability as the criteria, and the rolling speed, rolling passes, and compacted layer thickness as alternatives. Because of uncertainties in the criteria and alternatives, the cloud-fuzzy method, in which a fuzzy neural network is extended with a cloud model to handle uncertain and fuzzy problems more effectively, is introduced to determine the compaction quality. A case study is presented to evaluate the compaction quality of a hydropower project in China. The results indicate that the cloud-fuzzy model is feasible in relation to precision and makes up for the sole focus on precision by traditional methods. The proposed method provides a triple index for understanding compaction quality, which facilitates assessment of the compaction quality of an entire dam surface. 相似文献
10.
Approach for analyzing the ultimate strength of concrete filled steel tubular arch bridges with stiffening girder 总被引：2，自引：0，他引：2
ZHANG Zhi-cheng XIE Xu ZHANG He CHEN Heng-zhi 《浙江大学学报(A卷英文版)》2007,8(5):682-692
A convenient approach is proposed for analyzing the ultimate load carrying capacity of concrete filled steel tubular (CFST) arch bridge with stiffening girders. A fiber model beam element is specially used to simulate the stiffening girder and CFST arch rib. The geometric nonlinearity, material nonlinearity, influence of the construction process and the contribution of prestressing reinforcement are all taken into consideration. The accuracy of this method is validated by comparing its results with experimental results. Finally, the ultimate strength of an abnormal CFST arch bridge with stiffening girders is investigated and the effect of construction method is discussed. It is concluded that the construction process has little effect on the ultimate strength of the bridge. 相似文献
11.
Time, cost, and quality are three key control factors in rockfill dam construction, and the tradeoff among them is important. Research has focused on the construction time-cost-quality tradeoff for the planning or design phase, built on static empirical data. However, due to its intrinsic uncertainties, rockfill dam construction is a dynamic process which requires the tradeoff to adjust dynamically to changes in construction conditions. In this study, a dynamic time-cost-quality tradeoff (DTCQT) method is proposed to balance time, cost, and quality at any stage of the construction process. A time-cost-quality tradeoff model is established that considers time cost and quality cost. Time, cost, and quality are dynamically estimated based on real-time monitoring. The analytic hierarchy process (AHP) method is applied to quantify the decision preferences among time, cost, and quality as objective weights. In addition, an improved non-dominated sorting genetic algorithm (NSGA-II) coupled with the technique for order preference by similarity to ideal solution (TOPSIS) method is used to search for the optimal compromise solution. A case study project is analyzed to demonstrate the applicability of the method, and the efficiency of the proposed optimization method is compared with that of the linear weighted sum (LWS) and NSGA-II. 相似文献
12.
冯骏杰 《湖州职业技术学院学报》2014,12(3):55-59
提出一种考虑负荷不确定性的配电网无功规划优化的方法。该方法把不确定负荷表示成模糊数的形式并通过拟合误差服从正态分布来求取模糊集合参数;然后建立无功规划优化的模型。并采用模糊分析法,使模糊负荷能运用到求解模型中去;最后采用改进的二进制粒子群算法来求解无功优化模型。算例分析证明了此方法的有效性。 相似文献
13.
以重力式大坝工程施工为研究对象,研究利用BIM技术开展施工技术模拟。通过BIM技术模拟优化大坝混凝土施工技术参数,并基于AHP评价方法分析BIM技术在水利工程中的应用效果,评价效果为良,其中进度控制实施指标效果为优,可见BIM技术在水利工程中整体应用效果较佳。 相似文献
14.
介绍了土石坝筑坝材料本构模型参数反演计算原理,并采用基于免疫遗传算法的反演方法并结合某面板堆石坝筑坝材料大型现场压缩试验,对该面板坝筑坝材料的E—B模型参数进行反演计算,分析计算结果的合理性,说明此反演结果可以对筑坝材料的室内三轴试验结果进行修正,并为原型大坝的变形与应力分析提供更为可靠的依据。 相似文献
15.
The theory and method of system integration for the real-time monitoring of core rock-fill dam filling con- struction quality are studied in this paper. First, the importance analysis of system integration factors is carried out with the analytic hierarchy process. Then, according to the analysis result of integration factors, the conceptual model of system integration is built based on function integration, index integration, technology integration and information integration, the index structure of core rock-fill dam filling construction quality control is constructed and the method of function integration and technology integration is studied. The mathematical model of process monitoring is built according to monitoring objective, process and indexes. Research results have been applied in Nuozhadu core rock-fill dam construction management, realizing system integration through building appropriate monitoring work flow and comprehensive information platform of digital dam. 相似文献
16.
基于三维有限元计算软件ANSYS对某一高145 m的混凝土双曲拱坝进行开设大表孔与不开设表孔方案的计算对比分析,通过分析得出,高拱坝坝顶开设表孔对坝体应力的影响是局部的,主要集中在孔口周边,而对坝体下部几乎没有影响。最后,总结规律,希望为拱坝结构设计及体形优化提供参考。 相似文献
17.
Uncertainty in geological structural modeling, especially geological corrosion(a kind of karst cave), is a bottleneck that restricts the development and application of geological computer modeling and effect estimation. To solve this issue, a stochastic modeling method based on the random field theory is proposed in comparison with the deterministic geometric modeling method. Then the constraint random field modeling method and the random field modeling method without constrained parameters are compared and analyzed. A case study shows that the novel stochastic simulation method is an effective tool to describe the distribution characteristics of corrosion parameters and reflect the updated geological prospecting information. The influence of geological corrosion on the dam behavior can also be better analyzed by using the stochastic simulation method. At the same time, the unconfined random field ignores the sample location information and may lead to higher variability. Therefore, the constraint random field modeling method can provide a useful reference for the numerical analysis under complex geological conditions. 相似文献
18.
For river basin management, the reliability of the rating curves mainly depends on the accuracy and time period of the observed discharge and water level data. In the Elbe decision support system （DSS）, the rating curves are combined with the HEC-6 model to investigate the effects of river engineering measures on the Elbe River system. In such situations, the uncertainty originating from the HEC-6 model is of significant importance for the reliability of the rating curves and the corresponding DSS results. This paper proposes a two-step approach to analyze the uncertainty in the rating curves and propagate it into the Elbe DSS： analytic method and Latin Hypercube simulation. Via this approach the uncertainty and sensitivity of model outputs to input parameters are successfully investigated. The results show that the proposed approach is very efficient in investigating the effect of uncertainty and can play an important role in improving decision-making under uncertainty. 相似文献
19.
During the storehouse surface rolling construction of a core rockfilldam, the spreading thickness of dam face is an important factor that affects the construction quality of the dam storehouse' rolling surface and the overallquality of the entire dam. Currently, the method used to monitor and controlspreading thickness during the dam construction process is artificialsampling check after spreading, which makes it difficult to monitor the entire dam storehouse surface. In this paper, we present an in-depth study based on real-time monitoring and controltheory of storehouse surface rolling construction and obtain the rolling compaction thickness by analyzing the construction track of the rolling machine. Comparatively, the traditionalmethod can only analyze the rolling thickness of the dam storehouse surface after it has been compacted and cannot determine the thickness of the dam storehouse surface in realtime. To solve these problems, our system monitors the construction progress of the leveling machine and employs a real-time spreading thickness monitoring modelbased on the K-nearest neighbor algorithm. Taking the LHK core rockfilldam in Southwest China as an example, we performed real-time monitoring for the spreading thickness and conducted real-time interactive queries regarding the spreading thickness. This approach provides a new method for controlling the spreading thickness of the core rockfilldam storehouse surface. 相似文献
20.
有限元应力计算在某拱坝加高工程的应用 总被引：2，自引：0，他引：2
张美新 《长江工程职业技术学院学报》2008,25(1):21-23
拱坝加高的关键问题是加高后对坝踵处拉应力的影响以及新老坝体结合面完整性等,因此坝肩稳定、新老坝体的结合面和坝体应力是重要指标。本文以闽东水电站拱坝工程加高为例,根据拱坝的工作特点,采用有限元程序ANSYS对其进行了不同工况的坝体应力计算,根据计算结果进行分析,并提出一些建议。 相似文献