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841.
考虑沉桩与群桩间相互影响的复合模量计算方法   总被引:2,自引:1,他引:2  
总结了复合模量计算的研究现状;提出了考虑群桩间相互影响的复合地基模量计算公式,即由于邻桩对桩间土的加固作用而使复合模量比单桩模型的计算值有所增加,公式同时考虑了沉桩对桩间土模量的提高作用,最后通过算例验证了所提出的公式。  相似文献   
842.
喷粉桩复合地基的群桩效应的探讨及其载荷试验研究   总被引:3,自引:1,他引:3  
从复合地基的基本原理出发,讨论了群桩效应现象在复合地基存在的可能性,并通过喷粉桩复合地基的单桩,多桩复合地基载荷试验的对比研究,揭示了复合地基中的群桩效应现象。  相似文献   
843.
小城镇土地集约利用水平综合评价直接反映小城镇土地利用的集约程度,文章对小城镇土地集约利用水平综合评价的方法有益的探索,构建了一套小城镇土地集约利用水平综合评价的指标体系,采用多因素综合评价的方法,得到集约利用综合指数F,并通过比较分析探讨小城镇土地集约利用的空间分异特征及成因,从而达到定量衡量小城镇土地集约利用水平的目的。以重庆市北碚区为例的研究表明,小城镇土地集约利用水平综合评价采用多因素综合评价法是比较适宜的。  相似文献   
844.
用36GHz和9.2GHz微波辐射计测量了不同厚度的水面油膜的亮度温度,应用并矢格林函数及起伏逸散定理进行了理论模式的数值计算,同实验取得了基本一致的结果。  相似文献   
845.
岩爆岩石弹射性能综合指数 Krb判据   总被引:5,自引:0,他引:5       下载免费PDF全文
本文以正在施工的南盘江天生桥大型水电站引水隧洞中产生岩爆的石灰岩为试件,在电液闭路伺服控制刚性试验机上进行了大量的岩石弹射试验。依据荷载-位移全过程曲线,分析了有效弹射能 Weff 与岩爆岩石脆性指数 Ku、应力下降指数 Kσ以及弹性应变能指数 Kw 之间的关系,提出了岩爆岩石弹射性能综合指数 Krb判据。  相似文献   
846.
东疆阿齐山—黄山复合地体的沉积特征   总被引:3,自引:1,他引:3  
优地槽型阿齐山—黄山复合地体在石炭纪的沉积特征明显受其边界断裂带的控制。不同阶段各断裂带活动性质,活动强度的差异导致南北两亚地体沉积物成分、厚度的变化。阿齐山—黄山复合地体的演化历史可分为三个阶段,与边界断裂带的相应演化阶段关系密切。  相似文献   
847.
Tanlu fault zone is the largest strike-slip fault system in eastern China. Since it was discovered by aeromagnetics in 1960s, it has been widely concerned by scholars at home and abroad, and a lot of research has been done on its formation and evolution. At the same time, the Tanlu fault zone is also the main seismic structural zone in China, with an obvious characteristic of segmentation of seismicity. Major earthquakes are mostly concentrated in the Bohai section and Weifang-Jiashan section. For example, the largest earthquake occurring in the Bohai section is M7.4 earthquake, and the largest earthquake occurring in the Weifang-Jiashan section is M8.5 earthquake. Therefore, the research on the active structure of the Tanlu fault zone is mainly concentrated in these two sections. With the deepening of research, some scholars carried out a lot of research on the middle section of Tanlu fault zone, which is distributed in Shandong and northern Jiangsu Province, including five nearly parallel fault systems, i.e. Changyi-Dadian Fault(F1), Baifenzi-Fulaishan Fault(F2), Yishui-Tangtou Fault(F3), Tangwu-Gegou Fault(F4) and Anqiu-Juxian Fault(F5). They find that the faults F3 and F5 are still active since the late Quaternary. In recent years, we have got a further understanding of the geometric distribution, active age and active nature of Fault F5, and found that it is still active in Holocene. At the same time, the latest research on the extension of F5 into Anhui suggests that there is a late Pleistocene-Holocene fault existing near the Huaihe River in Anhui Province. The Tanlu fault zone extends into Anhui Province and the extension section is completely buried, especially in the Hefei Basin south of Dingyuan. At present, there is little research on the activity of this fault segment, and it is very difficult to study its geometric structure and active nature, and even whether the fault exists has not been clear. Precisely determining the distribution, active properties and the latest active time of the hidden faults under urban areas is of great significance not only for studying the rupture behavior and segmentation characteristics of the southern section of the Tanlu fault zone, but also for providing important basis for urban seismic fortification. By using the method of shallow seismic prospecting and the combined drilling geological section, this paper carries out a detailed exploration and research on the Wuyunshan-Hefei Fault, the west branch fault of Tanlu fault zone buried in Hefei Basin. Four shallow seismic prospecting lines and two rows of joint borehole profiles are laid across the fault in Hefei urban area from north to south. Using 14C, OSL and ESR dating methods, ages of 34 samples of borehole stratigraphic profiles are obtained. The results show that the youngest stratum dislocated by the Wuyunshan-Hefei Fault is the Mesopleistocene blue-gray clay layer, and its activity is characterized by reverse faulting, with a maximum vertical offset of 2.4m. The latest active age is late Mesopleistocene, and the depth of the shallowest upper breaking point is 17m. This study confirms that the west branch of Tanlu fault zone cuts through Hefei Basin and is still active since Quaternary. Its latest activity age in Hefei Basin is late of Middle Pleistocene, and the latest activity is characterized by thrusting. The research results enrich the understanding of the overall activity of Tanlu fault zone in the buried section of Hefei Basin and provide reliable basic data for earthquake monitoring, prediction and earthquake damage prevention in Anhui Province.  相似文献   
848.
北西走向的桥头集-东关断裂与郯庐断裂带南段相交切,横跨合肥盆地及其东缘的隆起区,在合肥盆地内呈隐伏状态。本研究跨桥头集-东关断裂合肥盆地段布设3条浅层地震勘探测线,揭示断裂浅部构造特征。解译出的FP1、FP2和FP3断层性质相同,倾向一致,上断点深度相近,反映出桥头集-东关断裂合肥盆地段是一条走向NW、倾向SW、具有逆断分量的断裂。3条浅层地震反射剖面中第四系的底界面反射波组TQ呈连续近水平展布,表明桥头集-东关断裂两侧的第四系厚度无明显变化。在浅震剖面解译的基础上,布设了1条跨断层钻孔联合剖面,剖面揭露出的第四系没有被错动。结合本区第四系地层发育情况及钻孔地层年龄分析,认为桥头集-东关断裂中更新世以来不活动。根据本文探测结果,尚不能排除桥头集-东关断裂早更新世有一定的弱活动。  相似文献   
849.
This study focused on the experimental examination of how hollow composite members perform when subjected to eccentric lateral loading that induces combined bending and torsional stresses. It was found that premature cracking degraded section integrity and interfered with steel–concrete interaction when members were subjected to combined bending and torsion. It was also found that members' bending capacities and ductilities were significantly reduced when the members were subjected to torsion. Relationships among member performance, magnitude of torsion, and sectional aspect ratios were studied to evaluate the torsional effects on member performances and to establish design references for hollow composite member constructions. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
850.
复合土钉墙是一种新型的支护技术,不同于传统的土钉支护。本文将复合土钉墙支护技术分别应用于饱和黄土地层和粉喷桩复合地层,并通过有限元模拟计算,对其在不同地层条件和不同开挖阶段的变形及其承载机理进行了分析研究,可以看出,复合土钉墙变形随地层条件的不同而不同,其承载机理也与传统土钉墙有较大差异。这些结论将为以后设计复合土钉墙和进行基坑开挖过程中事故的防范提供重要参考。  相似文献   
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