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71.
72.
土工合成材料界面作用特性的拉拔试验研究 总被引:12,自引:3,他引:9
在土工合成材料加筋土工程中,土工合成材料与填料的界面作用特性是最关键的技术指标,因此利用拉拔试验研究土工合成材料与填料的界面作用特性是非常必要的。以5种不同种类的国产土工合成材料为加筋材料,以砂和石灰粉煤灰为填料,比较了各种土工合成材料与填料的界面作用特性,试验表明:(1)石灰粉煤灰自重较轻,摩擦角高,并且比砂的拉拔系数相对偏高一倍左右,是理想的土工合成材料加筋土工程的填料;(2)土工合成材料的拉拔系数从高到低排序为涤纶纤维经编土工格栅最高,塑料拉伸土工格栅次之,土工网较低,土工织物最低;(3)不同填料、不同土工合成材料的拉拔系数相差较大,具体加筋土工程采用的拉拔系数需要通过拉拔试验确定。这些结论可指导土工合成材料的优选和研究加筋机理。 相似文献
73.
通过对博白县雷电灾害防御工作现状分析,找出博白县当前防雷工作突出问题,提出进一步做好雷电灾害防御工作的应对措施。 相似文献
74.
当今,我国地铁发展迅速,许多城市地铁线路已逐步形成网状结构,这样有利于换乘,节省空间,但在新建隧道下穿既有隧道时,施工对既有隧道的安全会造成一定影响。为了在不影响既有线路运营的情况下确保安全,自动化监测成为不可缺少的一部分。本文主要阐述测量机器人在隧道自动化监测中的应用。 相似文献
75.
结合宁波市杭州湾新区跨十塘横江桥工程实例,介绍了CASIO fx-4850P可编程计算器在钢结构桥梁工程安装测量过程中的应用。由于在现场测量过程中,钢结构节段的上口4个角点并不能完全通视。考虑到CASIO fx-4850P的便携性,特别设计了由上口3个角点推算第4个角点的程序,以便对节段的上口平面有所整体把握。在程序的设计过程中,利用高程系与平面系的独立性,避免列立复杂方程求解,而是将上口角点投影到XOY坐标平面,将问题简化为平面求解问题。 相似文献
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GPS-RTK技术在城市地籍测量中的应用 总被引:2,自引:0,他引:2
令狐义强 《测绘与空间地理信息》2011,34(3):108-109,115
随着科学技术的迅猛发展,城市地籍测量的方法和技术也得到了长足进步.GPS-RTK测量技术是GPS技术发展的新突破.该技术被广泛应用于城市地籍测量领域.本文主要就GPS-RTK的基本原理、基本配置、GPS-RTK的应用进行了阐述,最后讨论了GPS-RTK技术的优势和实际作业中的注意事项. 相似文献
78.
The present work reports on an in situ experimental test campaign carried out on abandoned traditional masonry houses after the 9th July 1998 earthquake that seriously hit the Faial island of Azores. For the testing purposes, an experimental test setup was developed based on a self‐equilibrated scheme, which is herein described reporting on the advantages and drawbacks of this in situ test setup. Five specimens were tested aiming at characterizing the out‐of‐plane behavior of stone masonry walls and strengthening solutions recommended for post‐earthquake interventions. A detailed comparison between solutions' efficiency is presented including a cost vs benefit analysis. In order to assess the efficiency of the developed test setup for other applications on stone masonry walls, an in‐plane test on an existing URM panel is also presented. Several related issues are discussed, namely the advantages of dealing with the real boundary conditions and the capacity of providing valuable information of the response, as well as a detailed analysis of the obtained results. The authors believe that this work provides an increase in knowledge on the seismic behavior of the existing masonry constructions, resulting from the development of an in situ test setup and the efficiency quantification of strengthening solutions. Therefore, the work is thought to positively contribute for the preservation of architectural heritage and for its seismic vulnerability reduction. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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The paper proposes a systematic comparison between two methods of analysis that are well established in the field of earthquake engineering: nonlinear dynamic analysis and nonlinear static procedure (NSP), applied to the out‐of‐plane seismic response of two masonry façades representative of many ancient Italian churches. The comparison is based on extensive numerical analyses, which focus on the flexural and torsional mechanisms, while the in‐plane damage mechanisms and the possible detachment between the façade and the lateral walls because of a poor connection have been presently disregarded. The computations, both in the static and in the dynamic field, are based on a rigid body and spring model specifically implemented for this issue, computationally efficient and equipped with a realistic model of damage and hysteresis at the mesoscale. An innovative aspect of this study is the heuristic modelling of three‐wythe masonry, to include some typical texture effects on the macroscale nonlinear response. For each façade, two different masonry textures were considered, performing extensive dynamic analyses that offered a detailed overview about the performance under earthquakes of different intensities. In parallel, NSP and the classical N2‐based seismic assessment were applied. A critical discussion and comparison of the results of the two methods is presented to rationally appraise limits and opportunities. In particular, flexural and twisting out‐of‐plane mechanisms were clearly appraised in the dynamic field, whereas NSPs were not always able to describe the collapse, because they missed the partial failures determined by higher vibration modes, as could be expected. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献