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考虑开挖面空间效应的围岩虚拟支护力分析
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作者 辛法 崔岚 张军 《地下空间与工程学报》 CSCD 北大核心 2019年第3期786-793,共8页
基于围岩与支护相互作用两阶段分析法,针对静水压力下的圆形隧道,提出了一种预测理想弹塑性、应变软化、弹脆塑性围岩下虚拟支护力的数值方法。根据该方法,首先给出了隧道纵向变形曲线与围岩特征曲线的求解程序,在此基础上,根据一定工... 基于围岩与支护相互作用两阶段分析法,针对静水压力下的圆形隧道,提出了一种预测理想弹塑性、应变软化、弹脆塑性围岩下虚拟支护力的数值方法。根据该方法,首先给出了隧道纵向变形曲线与围岩特征曲线的求解程序,在此基础上,根据一定工况下围岩应力应变一致性对虚拟支护力进行耦合求解。通过与其他方法的计算结果对比论证了本文方法的优势。同时还探讨了临界塑性软化系数、岩体质量、初始应力、剪胀系数对虚拟支护力与开挖面空间效应的影响规律,参数分析结果表明:许多关于隧道掘进的数值模拟研究或实际工程中,经常基于弹性假定计算应力释放率,相应的支护设计并不安全。 展开更多
关键词 隧道 围岩 支护 虚拟支护力 空间效应
Analysis of gateroad stability at two longwall mines based on field monitoring results and numerical model analysis 预览
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作者 Gabriel S.Esterhuizen David F.Gearhart +2 位作者 Ted Klemetti Heather Dougherty Mark van Dyke 《矿业科学技术学报:英文版》 CSCD 2019年第1期35-43,共9页
Coal mine longwall gateroads are subject to changing loading conditions induced by the advancing longwall face. The ground response and support requirements are closely related to the magnitude and orientation of the ... Coal mine longwall gateroads are subject to changing loading conditions induced by the advancing longwall face. The ground response and support requirements are closely related to the magnitude and orientation of the stress changes, as well as the local geology. This paper presents the monitoring results of gateroad response and support performance at two longwall mines at a 180-m and 600-m depth of cover.At the first mine, a three-entry gateroad layout was used. The second mine used a four-entry, yieldabutment-yield gateroad pillar system. Local ground deformation and support response were monitored at both sites. The monitoring period started during the development stage and continued during first panel retreat and up to second panel retreat. The two data sets were used to compare the response of the entries in two very different geotechnical settings and different gateroad layouts. The monitoring results were used to validate numerical models that simulate the loading conditions and entry response for these widely differing conditions. The validated models were used to compare the load path and ground response at the two mines. This paper demonstrates the potential for numerical models to assist mine engineers in optimizing longwall layouts and gateroad support systems. 展开更多
关键词 COAL MINING LONGWALL Gateroad SUPPORT NUMERICAL MODELS
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广州市地铁四号线南沙客运港站基坑开挖及支护方案探讨 预览
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作者 迟骋 《企业技术开发》 2019年第4期11-17,共7页
广州市地铁四号线南沙客运港站土建工程位于南沙区港前大道与科技大道交叉口,沿港前大道敷设于路下,与远期规划15号线垂直相交进行换乘。该站处于深厚淤泥之中,开挖及支护难度极大。文章对此问题进行深入探讨,研究成果为工程施工提供了... 广州市地铁四号线南沙客运港站土建工程位于南沙区港前大道与科技大道交叉口,沿港前大道敷设于路下,与远期规划15号线垂直相交进行换乘。该站处于深厚淤泥之中,开挖及支护难度极大。文章对此问题进行深入探讨,研究成果为工程施工提供了技术支持,也可为类似工程提供参考。 展开更多
关键词 基坑开挖 支护 方案 探讨 技术支持
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Partially decoupling and collar bonding of the encapsulated rebar rockbolts to improve their performance in seismic prone deep underground excavations 预览
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作者 Reza Masoudi Mostafa Sharifzadeh Masoud Ghorbani 《矿业科学技术学报:英文版》 CSCD 2019年第3期409-418,共10页
Rockbolt is widely employed all over the world as an effective ground reinforcement element in order to secure the underground workplaces.Ordinary encapsulated rebar or rebar rockbolt is most popular and commonly used... Rockbolt is widely employed all over the world as an effective ground reinforcement element in order to secure the underground workplaces.Ordinary encapsulated rebar or rebar rockbolt is most popular and commonly used as reinforcement in a ground support system because of its accessibility,cost effectiveness and easy practicability.Reinforcement elements in a seismic condition such as rock burst have to dissipate the energy release of the dynamic impact via their deformation and ultimate load capacity,knowing that the former is more important.In other words,achieving early stiff behaviour along with large deformation capacity in rockbolts are the goals for new development in rock reinforcement.Yielding rockbolts are expensive while some of them have large deformation capability with low ultimate load capacity.In this paper,modifications were made on encapsulation of rebar rockbolts to utilise it effectively as a yielding reinforcement in seismic conditions.Applying a sufficient decoupled length in the shank of rebar rockbolts which industry has regularly been using to control the bulking of the stress fractured ground,improves the deformation capacity of the bolt.Additionally,leaving a collar bonding underneath of the bearing pad and plate removes the weaknesses of the head anchorage of rockbolt.Therefore the dynamic performance of the bolt is improved by these easily applicable modifications.The behaviour and performance of encapsulated rockbolts have been discussed first,then the effects of modifications are illustrated.The proposed modification of the rebars is not only cost effective but also easy to apply in the field and improves the performance of reinforcements in seismic prone zones. 展开更多
关键词 Rockbolt Tunnel SUPPORT COLLAR BONDING SEISMIC rock SUPPORT Tunnelling
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地质构造对巷道支护的影响研究 预览
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作者 丁翼飞 《当代化工研究》 2019年第8期147-148,共2页
在煤矿的实际生产中,大阳泉矿所处区域的地质构造在一定程度上会对矿井的支护产生不同程度的影响。本文通过对常见的地质构造进行系统分析,进一步明确了不同地质构造对巷道支护的影响,综合分析可知,根据矿井实际情况采取针对性的支护方... 在煤矿的实际生产中,大阳泉矿所处区域的地质构造在一定程度上会对矿井的支护产生不同程度的影响。本文通过对常见的地质构造进行系统分析,进一步明确了不同地质构造对巷道支护的影响,综合分析可知,根据矿井实际情况采取针对性的支护方案在一定程度上能够有效提高巷道整体稳定性。 展开更多
关键词 煤矿 地质构造 支护 影响因素 防治
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综采工作面回撤巷道支护技术研究 预览
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作者 王海涛 《当代化工研究》 2019年第5期117-118,共2页
为了保证回撤巷道的安全,采用数值模拟、理论分析及现场实测的技术手段,对6101回采工作面回撤巷道的支护进行研究,结果表明采用的巷道支护技术能保证回撤,为综采工作面设备的快速回撤奠定了基础。
关键词 综采工作面 回撤巷道 支护
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An artificial intelligence based method for evaluating power grid node importance using network embedding and support vector regression
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作者 Hui-fang WANG Chen-yu ZHANG +1 位作者 Dong-yang LIN Ben-teng HE 《信息与电子工程前沿:英文版》 SCIE EI CSCD 2019年第6期816-828,共13页
The identification of important nodes in a power grid has considerable benefits for safety. Power networks vary in many aspects, such as scale and structure. An index system can hardly cover all the information in var... The identification of important nodes in a power grid has considerable benefits for safety. Power networks vary in many aspects, such as scale and structure. An index system can hardly cover all the information in various situations. Therefore, the efficiency of traditional methods using an index system is case-dependent and not universal. To solve this problem, an artificial intelligence based method is proposed for evaluating power grid node importance. First, using a network embedding approach, a feature extraction method is designed for power grid nodes, considering their structural and electrical information. Then, for a specific power network, steady-state and node fault transient simulations under various operation modes are performed to establish the sample set. The sample set can reflect the relationship between the node features and the corresponding importance. Finally, a support vector regression model is trained based on the optimized sample set for the later online use of importance evaluation. A case study demonstrates that the proposed method can effectively evaluate node importance for a power grid based on the information learned from the samples. Compared with traditional methods using an index system, the proposed method can avoid some possible bias. In addition, a particular sample set for each specific power network can be established under this artificial intelligence based framework, meeting the demand of universality. 展开更多
关键词 Power grid Artificial INTELLIGENCE Node importance Text-associated Deep WALK NETWORK EMBEDDING Support vector regression
吸收塔上部保温脚手架的搭设与计算 预览
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作者 彭艳 《化工设计通讯》 CAS 2019年第3期158-159,共2页
介绍了吸收塔浆池区室内布置时,吸收塔上部保温脚手架的搭设方法,以及因下部空间受限,设置于吸收塔外壁的脚手架支撑件的设计计算。
关键词 吸收塔 保温 脚手架 支撑件
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雷达干扰对防空导弹系统支援效果评估 预览
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作者 赵俊阳 刘湘伟 杨刚 《火力与指挥控制》 CSCD 北大核心 2019年第7期90-94,共5页
通过对比防空导弹系统得到雷达干扰支援前后的作战效能,评估雷达干扰的支援效果。以防空导弹拦截空袭飞机的概率为作战效能评估指标,并将其分解为防空导弹可发射批次、搜索雷达发现概率、制导雷达截获概率、防空导弹命中概率和目标的可... 通过对比防空导弹系统得到雷达干扰支援前后的作战效能,评估雷达干扰的支援效果。以防空导弹拦截空袭飞机的概率为作战效能评估指标,并将其分解为防空导弹可发射批次、搜索雷达发现概率、制导雷达截获概率、防空导弹命中概率和目标的可拦截性,分别计算雷达干扰支援前后上述5个参数的变化,进而得出支援前后成功拦截概率的差异。最后通过实例分析验证了评估方法的科学性和准确性。研究成果一定程度上弥补了雷达干扰与防空导弹结合使用后作战效能评估的短板,并为防空导弹的运用提供一定的理论依据。 展开更多
关键词 雷达干扰 防空导弹 支援 效能评估
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恒兴煤业近距离煤层巷道围岩支护稳定性研究 预览
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作者 李云 《山东煤炭科技》 2019年第7期61-63,共3页
恒兴煤业3号煤运输巷道布置于近距离煤层中,受上部煤层开采影响,巷道稳定性较差,为了控制回采巷道围岩,将数值计算拟合与工程实践两种研究方法综合利用,分析探讨巷道围岩稳定性控制的最佳支护方案及参数。结果表明,采用顶板锚杆5根、两... 恒兴煤业3号煤运输巷道布置于近距离煤层中,受上部煤层开采影响,巷道稳定性较差,为了控制回采巷道围岩,将数值计算拟合与工程实践两种研究方法综合利用,分析探讨巷道围岩稳定性控制的最佳支护方案及参数。结果表明,采用顶板锚杆5根、两帮各2根、长2.5m,顶板锚索2根、长6.3m的支护方案效果最佳。 展开更多
关键词 近距离 煤层 模拟 巷道 支护
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Machine learning methods for rockburst prediction-state-of-the-art review 预览
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作者 Yuanyuan Pu Derek B.Apel +1 位作者 Victor Liu Hani Mitri 《矿业科学技术学报:英文版》 CSCD 2019年第4期565-570,共6页
One of the most serious mining disasters in underground mines is rockburst phenomena.They can lead to injuries and even fatalities as well as damage to underground openings and mining equipment.This has forced many re... One of the most serious mining disasters in underground mines is rockburst phenomena.They can lead to injuries and even fatalities as well as damage to underground openings and mining equipment.This has forced many researchers to investigate alternative methods to predict the potential for rockburst occurrence.However,due to the highly complex relation between geological,mechanical and geometric parameters of the mining environment,the traditional mechanics-based prediction methods do not always yield precise results.With the emergence of machine learning methods,a breakthrough in the prediction of rockburst occurrence has become possible in recent years.This paper presents a state-ofthe-art review of various applications of machine learning methods for the prediction of rockburst potential.First,existing rockburst prediction methods are introduced,and the limitations of such methods are highlighted.A brief overview of typical machine learning methods and their main features as predictive tools is then presented.The current applications of machine learning models in rockburst prediction are surveyed,with related mechanisms,technical details and performance analysis. 展开更多
关键词 Rockburst prediction Burst liability Artificial neural network Support vector machine Deep learning
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某金属地下矿山灰岩破碎巷道支护方案比选 预览
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作者 张明新 陈广瑞 刘金涛 《世界有色金属》 2019年第14期207-208,共2页
文章主要分析了金属地下矿山灰岩破碎巷道支护方案,并经过相关的监测研究选出适用于金属地下矿山灰岩破碎巷道支护的方案。
关键词 地下矿山 支护 方案
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Behavior and functional modeling methods of doubly salient electromagnetic generators for aircraft electrical power system applications
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作者 Yanwu XU Zhuoran ZHANG +1 位作者 Li YU Yuke SHI 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第2期477-488,共12页
The Doubly Salient Electromagnetic Generator(DSEG) is a promising candidate in aircraft generator application due to the simplicity, robustness and reliability. However, the field windings and the armature windings ar... The Doubly Salient Electromagnetic Generator(DSEG) is a promising candidate in aircraft generator application due to the simplicity, robustness and reliability. However, the field windings and the armature windings are strongly coupled, which makes the inductance characteristics non-linear and too complex to model. The complex model with low precision also leads to difficulties in modeling and analysis of the entire aircraft Electrical Power System(EPS). A behavior level modeling method based on modified inductance Support Vector Machine(SVM) is proposed. The Finite Element Analysis(FEA) inductance data are modified based on the experiment results to improve the precision. A functional level modeling method based on input–output characteristics SVM is also proposed. The two modeling methods are applied to a 9 kW DSEG prototype. The steady state and transient process precision of the proposed methods are proved by comparing with the experiment results. Meanwhile, the modeling time consumption, the application time consumption and the calculation resource demand are compared. The DSEG behavior and functional modeling methods provide precious results with high efficiency, which accelerates theoretical analysis and expands the application foreground of the DSEG in the aircraft EPS. 展开更多
关键词 BEHAVIOR modeling DOUBLY salient electromagnetic machine FUNCTIONAL models NON-LINEAR analysis Support vector machines
综采工作面托顶煤顺槽超前支护技术研究 预览
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作者 吕东辉 李现朴 《山东煤炭科技》 2019年第7期64-65,71共3页
针对传统的综采工作面端头及超前支护采用单体柱配π型钢梁支护的缺陷,通过对22071综采工作面抬煤顺槽超前支护的研究,探索出了采用锚网索+端头及顺槽超前液压支架联合支护技术支护顺槽超前段,取得了良好的支护效果。
关键词 综采 顺槽 超前 支护
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Influence of longwall gateroad convergence on the process of mine ventilation network-model tests 预览
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作者 Andrzej Walentek Tomasz Janoszek +1 位作者 Stanislaw Prusek Aleksander Wrana 《矿业科学技术学报:英文版》 CSCD 2019年第4期585-590,共6页
Hard coal mines are required to constantly ventilate mine workings to ensure that the air composition is at a certain humidity and temperature level that is comfortable for underground mine workers,especially in deep ... Hard coal mines are required to constantly ventilate mine workings to ensure that the air composition is at a certain humidity and temperature level that is comfortable for underground mine workers,especially in deep deposits.All underground workings,which are part of the mine ventilation network,should be ventilated in a way that allows maintaining proper oxygen concentration not lower than 19%(by volume),and limits concentration of gases in the air such as methane,carbon monoxide or carbon dioxide.The air flow in the mine ventilation network may be disturbed due to the natural convergence(deformation)and lead to change in its original cross-section.Reducing the cross-sectional area of the mining excavation causes local resistances in the air flow and changes in aerodynamic potentials,which leads to emergency states in the mine ventilation network.This paper presents the results of numerical simulations of the influence of gateroad convergence on the ventilation process of a selected part of the mine ventilation network.The gateroad convergence was modelled with the finite element software PHASE 2.The influence of changes in the cross-sectional area of the gateroad on the ventilation process was carried out using the computational fluid dynamics software Ansys-Fluent. 展开更多
关键词 GEOMECHANICS CONVERGENCE Numerical modelling Ventilation process SUPPORT
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厚煤层回采巷道支护方案优化 预览
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作者 李庆芳 《山东煤炭科技》 2019年第3期31-33,共3页
针对矿井回采巷道变形量大的问题,在分析得出原始支护方案无法保证巷道围岩稳定原因后,通过优化支护方案和支护参数,对2206工作面运输巷掘进期间的巷道变化情况进行监测,证明新支护方案能够减少围岩变形量,较好控制围岩稳定性。
关键词 回采 巷道 支护 优化
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Antenna selection for MIMO system based on pattern recognition 预览
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作者 Ping Yang Jing Zhu +1 位作者 Yue Xiao Zhi Chen 《数字通信与网络:英文版》 2019年第1期34-39,共6页
This paper proposes a novel Multiple-Input Multiple-Output (MIMO) transmission scheme based on Pattern Recognition (PR), which is termed as the PR aided Transmission Antenna Selection MIMO (PR-TAS aided MIMO). As the ... This paper proposes a novel Multiple-Input Multiple-Output (MIMO) transmission scheme based on Pattern Recognition (PR), which is termed as the PR aided Transmission Antenna Selection MIMO (PR-TAS aided MIMO). As the conventional TAS algorithms need to search all possible legitimate antenna subsets, they may impose some redundant calculations. In order to avoid this problem, we employ some pattern recognition methods to carry out the TAS algorithm in this paper. To be specific, two PR algorithms, namely the K-Nearest Neighbor (KNN) algorithm and the Support Vector Machine (SVM) algorithm, are introduced and redesigned to obtain a TAS with lower complexity but higher efficiency. Moreover, in order to improve the performance of the SVM, we propose a new feature extraction of channel matrix for the TAS. Our simulation results show that the proposed KNN and SVM based PR-TAS algorithms are capable of striking a flexible tradeoff between the complexity and the Bit Error Rate (BER), and the new feature can effectively improve the BER performance compared with the conventional feature extraction method. 展开更多
关键词 ANTENNA selection K-nearest NEIGHBORS MULTIPLE-INPUT multiple-output Pattern RECOGNITION Support VECTOR machine
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高档普采工作面沿空留巷支护方案优化 预览
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作者 韩海军 《山东煤炭科技》 2019年第7期72-74,共3页
为更加有效地控制沿空留巷巷道的围岩位移量,通过对干河煤矿1-230工作面沿空留巷支护现状分析,决定采用巷道顶板补强、优化工作面超前、滞后支护方式及改变矸石袋摆放方式等措施,将原有支护方案进行优化设计。工程实践表明:优化后的巷... 为更加有效地控制沿空留巷巷道的围岩位移量,通过对干河煤矿1-230工作面沿空留巷支护现状分析,决定采用巷道顶板补强、优化工作面超前、滞后支护方式及改变矸石袋摆放方式等措施,将原有支护方案进行优化设计。工程实践表明:优化后的巷道围岩变形量明显减小。 展开更多
关键词 沿空留巷 支护 优化
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以生态循环产业化支撑村镇生态文明建设 预览
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作者 占明飞 宁军 +1 位作者 袁红军 张大标 《安徽农学通报》 2019年第4期1-2,21共3页
生态文明是继农业文明、工业文明之后又一全新的文明观,其强调人类在追求富有生产成果权利的同时,应该保持与自然的和谐关系,而生态文明建设就是践行人与自然和谐的必经之路。村镇作为生态文明建设的重地,其环境污染有其特殊性,必须结... 生态文明是继农业文明、工业文明之后又一全新的文明观,其强调人类在追求富有生产成果权利的同时,应该保持与自然的和谐关系,而生态文明建设就是践行人与自然和谐的必经之路。村镇作为生态文明建设的重地,其环境污染有其特殊性,必须结合村镇本身的特点,采取针对性治理措施。农村污染的治理必须结合农业生产,打造循环产业平台,实现治理的可持续性,同时还要理清社会、环境、生态三大关系,找到农村问题的根源,最终实现天地人的循环统一,为建设村镇生态文明服务。 展开更多
关键词 生态文明 循环产业 支撑
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高架车站钢结构屋盖预埋件破坏机理及布置优化 预览
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作者 李帆 张守龙 赵连政 《中国市政工程》 2019年第2期129-133,146共6页
以青岛轨道交通L8胶东镇站为例,建立预埋件节点模型,对比分析不同数量、间距锚筋工况下埋件节点的受力状态和破坏形式;对数值计算和工程实际进行分析。研究表明:在正常使用极限工况下预埋件节点破坏是剪力控制型,剪应力超限位置主要集... 以青岛轨道交通L8胶东镇站为例,建立预埋件节点模型,对比分析不同数量、间距锚筋工况下埋件节点的受力状态和破坏形式;对数值计算和工程实际进行分析。研究表明:在正常使用极限工况下预埋件节点破坏是剪力控制型,剪应力超限位置主要集中在锚板下部;在地震工况下,预埋节点破坏转变为拉剪共同控制,锚筋出现较大拉力和剪力,节点滑移破坏位置从锚板下部转为施加荷载附近。此外,双节点较单节点能更好降低剪应力增长速度,但应力变化不大;锚筋灌浆料的作用明显。因此,浇筑过程中混凝土密实程度,是保证锚筋抗拔性能的另一关键因素。依据研究成果,优化锚筋数量和布局,能减小锚筋使用量42%,与工程实际现场监测数据进行对比,位移偏差率小于15%,数值计算合理有效。 展开更多
关键词 高架车站 钢结构屋盖 支座 预埋件 设计施工方案
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