Results 71 to 80 of about 3,029 (144)
Determination of ultimate bearing capacity of pile under static load test based on cusp catastrophe model [PDF]
There are many analysis methods to determine the ultimate bearing capacity of single pile by using the load-settlement curve obtained from the static load test, but so far, reasonable and theoretical calculation method to solve the ultimate bearing ...
Jibao YANG
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Guangtongxin yanjiu, 2018 针对线性啁啾光栅反射谱有震荡、两侧有旁瓣等问题,从耦合模理论出发,研究了调制深度Δn、光栅长度L和啁啾系数C等对其反射谱的影响,深入探讨了重要参数与特性的关系。提出了基于折射率补偿的非对称变迹优化方法,探寻了有效的变迹函数、补偿系数和最佳比例。结果表明,随着L（5100mm）、Δn(10-510-3)和C（0.010.2nm/cm）的增大,峰值都向长波长方向漂移,3dB带宽都增大,分别为1.79、1.26和1.71nm,且基本成线性关系;L较小时,反射谱顶部有较大震荡;Δn较大时,反射谱两侧出现明显旁瓣。
孙瑞霞, 李炜, 赵发, 王宗乾
doaj
Jianzhu Gangjiegou Jinzhan, 2022 为评估钢框架结构在火灾下抗震性能的损伤程度，提出基于钢材力学性能折减和基准刚度法的钢框架结构火灾损伤评估方法。对火灾不同温度工况下的钢框架构件进行损伤敏感度分析，研究不同温度工况与钢框架梁、柱的损伤关系；在不同楼层火灾下识别损伤结构模态参数，以损伤前的楼层层间刚度为基准，揭示钢框架结构不同楼层、梁柱构件、中跨和边跨火灾损伤对楼层损伤的影响规律；最终获得楼层损伤与整体结构损伤的关系，建立钢框架结构火灾下抗震性能损伤演化模型。研究成果可为建立不同温度工况下钢框架结构抗震性能的损伤模型提供理论基础 ...
李宁, 刘纪陆, 赵崛
doaj
Research status and prospect of rock breaking form in mechanized excavation of mining hard rock roadway [PDF]
Rapid excavation of hard rock tunnels was a crucial aspect in achieving intelligent and efficient coal mining. Cantilever roadheaders, TBMs, and bottom cutting equipment are all attempting to address this challenge.
Chao LI +4 more
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Prediction of water inflow after excavation of underground chamber group with long span and high buried depth [PDF]
Predict the water inflow after excavation of large underground caverns is crucial for the safe construction and operation of underground engineering. To predict the water inflow of underground caverns after excavation and provide guidance for drainage ...
Guanghong JU +5 more
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Jianzhu Gangjiegou Jinzhan, 2008 按照《钢结构设计规范》（GB 50017-2003）计算组合梁考虑滑移后的折算刚度时,会遇到栓钉数量增加,刚度反而下降的现象。本文提出了新的折算刚度表达式,引入了钢与混凝土的组合作用系数来表征钢和混凝土轴压刚度通过抗剪件的作用而形成的组合作用的程度,采用考虑滑移影响的组合梁计算理论,求出了均布荷载下简支梁挠度的表达式,得到精度很高的简化计算公式,考察了栓钉抗滑移刚度值的确定方法,通过简单的分析,本文提出了折减刚度的计算公式,并与试验结果对比。将本文公式与规范计算公式和试验结果的对比,建议公式的误差更小 ...
童根树, 夏骏
doaj
Effect of retaining wall leakage on the deformation behavior of foundation pit in water-rich sandy strata [PDF]
Aiming at the disaster problem caused by leakage of water and sand in deep excavation, it is of great significance to reveal the evolution of foundation pit leakage disaster and its control method for underground engineering construction safety. Based on
Guolin YANG +3 more
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Failure depths of stope floors under dynamic loading induced by roof breaking [PDF]
ObjectiveAccurately assessing the failure depths of stope floors is crucial for assessing floor water inrush risks. Conventional theoretical models for calculating the failure depths generally merely consider static loads from the support pressure and ...
Bo XU +5 more
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Zhendong Ceshi yu Zhenduan为研究管道过流产生的流激振动对穿管堤防稳定性的影响，以广东省某穿管堤防为例，首先，建立管道‑堤防三维有限元模型，依据渗流计算确定最不利穿管工况，得到穿管堤防最大渗透力；其次，根据实测振动响应反演流激振动荷载，结合有限元动力法与强度折减法进行边坡动力稳定性分析；最后，采用间接耦合法实现渗透力‑流激振动多荷载耦合，研究渗流与流激振动对边坡稳定性的影响。结果表明：在仅考虑渗流作用下，穿管堤防上、中、下3种穿管工况安全系数分别降低15.0%、5.4%和16.5%；在渗透力‑流激振动耦合作用下 ...
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Pressure distribution and fluid migration law of gas lift reverse circulation well washing flow field in drilling sinking [PDF]
In order to reveal the pressure distribution and fluid migration law of the gas lift reverse circulation washing flow field in drilling method, the ø5m advanced drilling of the north wind well in Taohutu coal mine was taken as the research background ...
Chuanxin RONG +5 more
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