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21.
本文对土钉墙的变形影响因素进行分析和简化 ,并通过与土钉墙稳定性分析影响因素的比较 ,得出两者在参数上的近似一致性 ;利用土钉墙位移监测资料和稳定性分析结果 ,总结出工程意义上的土钉墙变形和整体稳定安全系数之间的关系曲线 ,可以用于土钉墙的变形预测 相似文献
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Improved economy and speed of construction can be achieved through the use of prefabricated structural members. As a step toward the advancement of prefabricated substructures, a precast composite column for seismic regions is proposed in this paper. Concrete-encased composite columns with core structural steel can be utilized for a fast construction method using steel connections. Six concrete-encased composite specimens with low steel ratio were fabricated. Quasi-static tests were conducted to investigate the cyclic response of the prefabricated composite columns. For composite columns with bolt connections, the cyclic behavior in terms of ultimate load and post-cracking behavior was enhanced significantly as the transverse reinforcement ratio increases. Higher prestressing gave greater flexural strength to the composite columns with prestressing and better energy absorption capacity, while displacement ductility of the prestressed composite column was decreased as the prestressing increased. 相似文献
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通过时南京市茶南基坑支护结构的深层水平位移、沉降、基坑水平位移、支撑轴力监测,得出了基坑周边水平位移及深层土体的水平位移随时间的变化曲线;周边建筑物的沉降随基坑开挖的变化关系;支撑轴力随时问的变化曲线。并时这些变化曲线进行了研究分析。 相似文献
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This paper presents a study of local thermal sensation (LTS) and comfort in a field environmental chamber (FEC) served by displacement ventilation (DV) system. The FEC, 11.12 m (L)×7.53 m (W)×2.60 m (H), simulates a typical office layout. A total of 60 tropically acclimatized subjects, 30 male and 30 female, were engaged in sedentary office work for 3 h. Subjects were exposed to three vertical air temperature gradients, nominally 1, 3 and 5 K/m, between 0.1 and 1.1 m heights and three room air temperatures of 20, 23 and 26 °C at 0.6 m height. The objective of this study is to investigate the mutual effect of local and overall thermal sensation (OTS) and comfort in DV environment. The results show that in a space served by DV system, at OTS close to neutral, local thermal discomfort decreased with the increase of room air temperature. The OTS of occupants was mainly affected by LTS at the arm, calf, foot, back and hand. Local thermal discomfort was affected by both LTS and OTS. At overall cold thermal sensation, all body segments prefer slightly warm sensation. At overall slightly warm thermal sensation, all body segments prefer slightly cool sensation. 相似文献
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Clarence W. DE SILVA 《国外电子测量技术》2020,7(3):1-14
为了提高超宽带雷达生命信号检测准确率,提出了一种改进型YOLOV3检测算法。考虑到超宽带雷达探测的人体呼吸信号成像后宽高相差较大,采用多尺度训练时网络对宽高的敏感程度不一样,因此在设计损失函数时,对宽高损失给予不同的权重系数。为了提高网络通道以及空间特征表达能力,使得网络能够扩大对目标特征区域的感知范围,因此将通道注意力与空间注意力结构(CBAM)嵌入到YOLOV3基础网络Darknet53的每个shortcut层,得到CBAM-YOLOV3网络结构。对比改进前后的算法。实验结果表明,改进后的算法在IoU阈值为0.5时,mAP为98.09%,提升3.90%,在阈值为0.75时,mAP为76.49%,提升16.48%。 相似文献
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Construction projects continue to suffer delays. Things go wrong and the project's completion date gets pushed back, with someone to be blamed for it. In practice, attempts are made to identify the causes of delays and schedules are modified to incorporate revised duration and new project time. The analysis itself is usually complex and can be aided by a computerized approach. This paper discusses different delay analysis techniques that are currently used by practitioners in the construction industry. It also discusses a proposed new delay analysis technique called the Isolated Delay Type (IDT). These techniques were tested against a case example and their strengths and weaknesses highlighted. The new technique can be used as a standalone module for delay analysis or could be incorporated within a computer system for construction delay analysis and claims preparation called Computerized Delay Claims Analysis (CDCA) that integrates different software including an expert system and management software such as scheduling and a database or spreadsheet. 相似文献
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The objective of this study is to show that the core competence approach has validity when applied to construction. The focus is on the analysis of the fit between market strategies of firms in the building industry and their core capabilities. Certain strategies require specific core capabilities and key external and internal conditions supporting these capabilities. The resource-based approach focuses on the conditions in a firm, the internal capabilities, and supports a core capability that is demanded. The network literature will be related to external conditions that support a core capability of a firm active in a certain market. In a multiple case study, firms are analysed that are involved in different stages of the building process. The case studies demonstrate firms with consistent patterns of market strategies, core capabilities, and supporting internal and external conditions. The specific core capability of the firm under investigation determines the types of external and internal conditions that are critical. 相似文献