共查询到20条相似文献,搜索用时 187 毫秒
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目前住宅结构多采用现浇板,一般尺寸多为双向板体系,其尺寸从(3.0m×3.0m)~(5.0m×10.0m)。由于住宅结构均布活荷载标准值为2kN/m2,准永久值系数为0.4,住宅的永久荷载标准值为自重加上不超过1kN/m2的面层荷载,故组合极为方便。住宅板的裂缝宽度应控制在0.3mm以内,板的挠度应控制为短跨长度的1/200,且应满足板内穿管线的要求等。根据沪建(2001)第0907号文的规定,住宅楼板板厚不宜小于110mm,卫生间板厚不应小于90mm;当短跨长度大于3.9m时,钢筋应双层双向布置,且主筋不小于8@150。从经济角度出发,板的厚度不宜太厚,以免自重过大、配筋率太低,… 相似文献
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深圳东环立交桥工程 (V标 )采用 12 0 0 m m冲孔桩基 ,双桩承台为5 .6 m× 2 .8m× 1.5 m。施工过程中 ,出现较多桩位与一地下排水箱涵 (尺寸为2 .5 m× 2 .5 m× 2 .0 m)相遇 ,经多方努力 ,调整了桩位 ,使大部分桩均移至箱涵范围之外 ,仅在箱涵的沉淀检查池(尺寸为 9m× 9m× 4m)范围内作穿过施工 ,节省造价约 18万元。钢筋混凝土沉淀检查池埋深 3m,上下板厚均为30 0 mm ,内配双层双向14mm@15 0 mm钢筋。施工期间 ,池内沉淀有深约 1.0 m左右淤泥 ,上层流动污水深约 1.5 m。施工工艺如下 :基坑开挖→顶板 2 .5 m钢筋混凝土洞拆除→搭设… 相似文献
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通过有限元对线荷载作用下的钢筋混凝土双向板进行计算,并对计算所得到的数据进行分析,得出了钢筋混凝土双向板在线荷载作用下内力的一种简化计算方法。对此简化计算方法进行验算,其可以满足工程要求,可供工程设计人员参考。 相似文献
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通过有限元对线荷载作用下的钢筋混凝土双向板进行计算,并对计算所得到的数据进行分析,得出了钢筋混凝土双向板在线荷载作用下内力的一种简化计算方法。对此简化计算方法进行验算,可以满足工程要求,可供工程设计人员参考。 相似文献
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针对路堤荷载下双向增强复合地基受力变形特性,以单桩有效影响范围内的路堤与复合地基为分析对象,引入大挠度环形薄板考虑加筋垫层的“柔性筏板效应”与“拉膜效应”,同时通过假定桩土相对位移模式,考虑地基成层性,从而建立了路堤、水平加筋体、桩体、桩间土协调变形三维模型,获得了路堤荷载作用下双向增强复合地基的荷载分担比及沉降计算方法。采用某工程试验数据对该计算方法进行验证,同时分析了路堤高度、桩帽宽度、筋材抗拉模量对中性点位置、桩土差异沉降以及复合薄板中面最大拉应力的影响,结果表明该方法所求得的荷载分担比及沉降与实测值较为接近,证明了其合理性。 相似文献
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工程结构矩形板设计中,常以边长比3作为单向板和双向板的划分界限,单向板设计中,认为荷载主要在短边方向传递,从而只计算一个方向的内力,并按照此结果配筋,在长边方向上按照构造配筋。这种方法在大部分荷载作用下是合理的,但是在线荷载作用下引起的内力在两个方向都比较显著。文章利用弹性力学理论对矩形四边简支板在线荷载作用下的内力进行计算分析,并与单向板理论进行比较,总结出内力变化的规律。 相似文献
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Investigation of block foundations resting on soil–rock and rock–rock media under coupled vibrations
In the present study,the dynamic response of block foundations of different equivalent radius to mass(R_o/m) ratios under coupled vibrations is investigated for various homogeneous and layered systems.The frequency-dependent stiffness and damping of foundation resting on homogeneous soils and rocks are determined using the half-space theory.The dynamic response characteristics of foundation resting on the layered system considering rock-rock combination are evaluated using finite element program with transmitting boundaries.Frequencies versus amplitude responses of block foundation are obtained for both translational and rotational motion.A new methodology is proposed for determination of dynamic response of block foundations resting on soil-rock and weathered rock-rock system in the form of equations and graphs.The variations of dimensionless natural frequency and dimensionless resonant amplitude with shear wave velocity ratio are investigated for different thicknesses of top soil/weathered rock layer.The dynamic behaviors of block foundations are also analyzed for different rock-rock systems by considering sandstone,shale and limestone underlain by basalt.The variations of stiffness,damping and amplitudes of block foundations with frequency are shown in this study for various rock—rock combinations.In the analysis,two resonant peaks are observed at two different frequencies for both translational and rotational motion.It is observed that the dimensionless resonant amplitudes decrease and natural frequencies increase with increase in shear wave velocity ratio.Finally,the parametric study is performed for block foundations with dimensions of 4 m × 3 m × 2 m and 8m×5m×2m by using generalized graphs.The variations of natural frequency and peak displacement amplitude are also studied for different top layer thicknesses and eccentric moments. 相似文献
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中谷粮油集团公司所属国家储备粮库天津武清国家粮食储备库为500亿斤建设库点之一,建设仓容3亿斤。由7栋36m×78m及3栋36m×66m钢结构门式刚架平房仓组成,堆粮高度为7.5m。根据提升功能专项批复文件,对平房仓内彩钢板屋顶进行保温、密封处理,处理面积为32500m2。 相似文献
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因地制宜 ,采用散驳组拼成浮吊船组 ,并采取不同于传统的动臂式与扒杆式浮吊装置 ,以无缝钢管构建成简易、经济、实用的柱式“井”字型吊架 ,完成长 60m、宽 7m、高 2m ,重 2 0 8t的钢箱梁浮运与浮吊任务 相似文献
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Kamran Esmaieli John Hadjigeorgiou Martin Grenon 《International Journal of Rock Mechanics and Mining Sciences》2010,47(6):915-926
This paper uses a case study from Brunswick Mine in Canada to determine a representative elementary volume (REV) of a jointed rock mass in the vicinity of important underground infrastructure. The equivalent geometrical and mechanical property REV sizes were determined based on fracture systems modeling and numerical experiments on a synthetic rock mass. Structural data collected in massive sulphides were used to generate a large fracture system model (FSM), 40 m×40 m×40 m. This FSM was validated and subsequently sampled to procure 40 cubic specimens with a height to width ratio of 2 based on sample width from 0.05 to 10 m. The specimens were introduced into a 3D particle flow code (PFC3D) model to create synthetic rock mass (SRM) samples. The geometrical REV of the rock mass was determined based on the number of fractures in each sampled volume (P30) and the volumetric fracture intensity (P32) of the samples. The mechanical REV was estimated based on the uniaxial compressive strength (UCS) and elastic modulus (E) of the synthetic rock mass samples.The REV size of the rock mass was determined based on a series of statistical tests. The T-test was used to assess whether the means of the samples were statistically different from each other and the F-test to compare the calculated variance. Finally, the coefficient of variation, for the synthetic rock mass geometrical and mechanical properties, was plotted against sample size. For this particular site the estimated geometrical REV size of the rock mass was 3.5 m×3.5 m×7 m, while the mechanical property REV size was 7 m×7 m×14 m. Consequently, for engineering purposes the largest volume (7 m×7 m×14 m) can be considered as the REV size for this rock mass. 相似文献
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哈尔滨新吉商场为地下 1层 ,地上 2层的公共建筑。地上 2层平面布置呈“凹”形 ,凹入区域的面积为 8.4m× 15.0m ,建设单位要求在此区域的地下室顶上补建 2层。凹入区域的东、南、西三侧均为地下 1层 ,地上 2层为框架结构 ,针对凹入区域的四角均设有 1个框架柱的特点 ,提出了“悬吊扩建改造法”和“承托扩建改造法”两种扩建改造设计方案 ,分别介绍了这两种方案的设计思路、连接节点构造措施及建造过程中应注意的问题。可供设计建造同类工程时参考 相似文献
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