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1.
为考察再生混凝土空心砌块砌体的受压性能,制作了再生混凝土骨料替代率为75%、抗压强度平均值达到8.60 MPa的再生混凝土小型空心砌块,进行了再生混凝土空心砌块砌体受压变形性能试验,研究该种砌体在竖向荷载作用下的受力全过程和破坏形态,分析了砌体的受压应力-应变曲线和弹性模量.结果表明:该种砌体的受压性能和破坏特征和普通混凝土砌块砌体基本一样;该种砌体的抗压强度和弹性模量随砂浆强度的增大而提高.通过对试验数据的回归分析,再生混凝土空心砌块砌体的弹性模量及轴心抗压强度可采用GB 50003—2010《砌体结构设计规范》中的相关公式进行计算,提出了再生混凝土砌块砌体受压应力-应变关系上升段计算公式,计算与试验结果吻合较好.  相似文献   

2.
针对混凝土竖孔空心砌块存在的热、渗、裂等问题,提出并研究了一种混凝土横孔空心砌块.通过对9组(共54个)这种混凝土横孔砌块砌体的受压性能试验研究,了解了这种新型横孔砌块砌体的变形特征及破坏机理.基于试验结果并参考现行国家规范,提出了这种新型横孔砌块砌体的抗压强度计算方法.通过引入砌体对数型应力-应变关系模型,得到了这种新型横孔砌块受压应力-应变计算公式和弹性模量计算方法,对比结果表明,弹性模量计算值与试验值吻合良好.本文工作解决了新型横孔砌块抗压强度设计问题,为单轴受压下新型横孔砌块的内力分析和有限元分析提供了重要依据.  相似文献   

3.
具有大孔洞率和高粉煤灰掺量的蒸压钢纤维粉煤灰砌块是一种新型墙体材料。对于墙体材料,高粉煤灰掺量能够更多地利用粉煤灰固体废料。制作成大孔洞率的砌块,则具有更好的保温性能。对孔洞率为35%和粉煤灰掺量为50%的砌块砌体,采用在砌体表面粘贴应变片的试验方法,研究了砌体短柱受压过程中的应力-应变关系。试验结果表明,利用对数型关系对大孔洞率和高粉煤灰掺量的蒸压钢纤维粉煤灰砌体的应力-应变关系进行拟合,经过最小二乘法统计分析,其弹性特征值范围为624到804之间。大孔洞率蒸压钢纤维粉煤灰砌块的本构关系研究为该种材料的应用提供试验数据。  相似文献   

4.
针对传统砌体填充墙在强烈地震荷载下常表现出低变形能力和高损伤特性,严重影响钢筋混凝土框架的延性的问题,本文开发了一种环境友好、经济高效且结构有益的剑麻纤维砌体填充砌体单元,并设计了3种配套延性砌筑砂浆。通过对砌体进行抗压和抗剪试验,获得了其应力-应变曲线、承载力和破坏模式等试验数据。结果表明:延性砌块-延性砂浆砌体在受力方向上呈现出无主裂缝的多缝开裂破坏模式,且抗压延性和剪切延性显著提高。根据相关规范提供的计算公式,得到了适用于新型砌体的抗压强度值;延性砌块-延性砂浆砌体的抗剪强度远超普通砌块砌体,并通过线性回归建立了适用于新型砌体的抗剪承载力计算公式。值得注意的是,延性砌块-延性砂浆砌体的变形能力远超延性砌块-普通砂浆砌体和普通砌块砌体,可应用于增强框架填充墙结构的地震安全性。  相似文献   

5.
砌体及砌体材料弹性模量取值的研究   总被引:1,自引:0,他引:1  
从3种不同途径研究砌体弹性模量取值,即:按试验结果进行统计,得到砼砌块砌体以及砖、砌块和砂浆的弹性模量表达式;由砌体受压本构关系推导得到砖砌体、砼砌块砌体弹性模量表达式;由砖、砌块、砂浆弹性模量表达式建立砖砌体、砼砌块砌体弹性模量表达式.由此3种弹性模性的表达式其计算结果与试验结果、我国现行规范取值吻合较好,为研究砌体结构受力性能和破坏机理及进行有限元分析提供了基础资料.  相似文献   

6.
对空心粘土砖、加气混凝土砌块、陶粒混凝土砌块、混凝土空心砌块Ⅰ和混凝土空心砌块Ⅱ等5种常用新型墙材砌体的抗压性能和抗剪性能进行试验,并与烧结普通砖砌体进行对比.研究结果表明:砌块的抗压强度与砌块的制作工艺和质量和有关,空心砌块的强度还与肋板的分布、孔洞的大小和面板的厚度有关;砌体随着荷载的增大,裂缝增多、延伸,并扩展至砌体各面,最终失去承载能力被破坏;砌体的抗剪强度与砌块的表面光滑度和界面的咬合程度有直接关系.  相似文献   

7.
灌孔混凝土砌块砌体受压性能研究   总被引:1,自引:1,他引:1  
通过对灌孔混凝土砌块砌体中混凝土芯柱三向受压应力状态进行分析,提出了适用于灌孔混凝土受压弹性模量的计算方法.同时,基于大量的试验结果,提出了适用于灌孔混凝土砌块砌体的泊松比、峰值应变、极限应变等参数,并引入到Domingo J.Carreira等提出的混凝土本构模型中,得出了适用于灌孔混凝土砌块砌体受压的应力-应变全曲线公式.对比结果表明,计算值与试验结果吻合良好,可供灌孔混凝土砌块砌体结构设计和研究参考.  相似文献   

8.
砼砌块砌体中材料强度匹配问题是工程设计中需要解决的问题.综述了国内外学者对砌体受压性能的研究成果,分析并总结了影响砌体抗压强度的主要因素.依据芯柱和砌块竖向变形协调原理,推导得到了灌孔砼砌块砌体中灌孔砼强度与砌块强度之间的关系表达式,据此编制了灌孔砼砌块砌体材料强度的最佳组合表,可指导工程设计.该研究成果丰富了砌体结构的基本理论,为规范条款提供了理论依据,同时对灌孔砼砌块砌体在工程中的应用具有参考价值.  相似文献   

9.
文章主要分析了新型自保温混凝土砌块砌体的弹性模量试验,对其受压应力-应变曲线变化规律进行研究;通过深入对比分析公式计算数值与试验结果,证实其试验数据的可靠性、收敛性。与此同时,在试验条件下测得的新型自保温混凝土砌块砌体的弹性模量值较混凝土空心砌块砌体的弹性模量大,提示该砌块砌体的抗变形能力很好,在同条件下可取代一般的混凝土空心砌块。  相似文献   

10.
目的研究竖向灰缝处有无砂浆对砌体抗弯性能的影响,并对此类无砂浆砌体是否满足砌体结构规范要求进行论证.方法笔者分别以竖向灰缝处有无砂浆、竖向灰缝处砌块截面形式为参数,进行砌体沿齿缝截面的弯曲抗拉试验,对比分析各参数对砌体沿齿缝截面弯曲抗拉强度的影响.结果竖向灰缝处砌块截面形式为企口的竖向无砂浆砌体沿齿缝截面弯曲抗拉强度大于截面形式为平口的竖向无砂浆砌体,而竖向有砂浆的平口砌体沿齿缝截面弯曲抗拉强度均大于竖向无砂浆砌体;竖向有砂浆的平口砌体和竖向无砂浆的企口砌体沿齿缝截面的弯曲抗拉强度值均符合砌体规范要求,而竖向无砂浆平口砌体沿齿缝截面的弯曲抗拉强度值不符合砌体规范要求.结论在砌块块体之间几何互锁的基础上,能够实现砌体的无砂浆砌筑,为促进无砂浆砌体的推广提供了有效途径.并提出竖向灰缝处有无砂浆砌体沿齿缝截面弯曲抗拉强度平均值的建议计算公式.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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