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1.
陈永锋 《科技资讯》2006,(18):109-110
本文分析了砌体结构裂缝的成因,对温度裂缝、收缩裂缝以及沉降裂缝的产生机理进行了分析,提供了温度应力、温度变形和干缩变形的估算方法,讨论了影响砌体结构开裂的因素。  相似文献   

2.
张武 《科技信息》2009,(29):I0465-I0465,I0753
目前,砌体裂缝的类型越来越复杂,形态各异,有的甚至影响到了建筑物的结构,这一点已引起建筑界有关专家的高度重视:建筑物中常见的砌体裂缝基本类型有:地基不均匀沉降裂缝;承载能力不足引起的砌体裂缝;温度收缩裂缝;材料质量及施工问题造成的砌体裂缝:建筑构造不良造成的砌体裂缝。  相似文献   

3.
对砌体结构温度裂缝现象从材料力学方面作了扼要分析,并结合砌体结构形式及设计中的一些问题,提出了设计、施工中应采取的防治温度裂缝的一些方法。  相似文献   

4.
砌体结构是我国建筑工程中量大面广的最常用的结构形式.但其裂缝问题,尤其温度裂缝问题是一个长期困扰着建筑工程技术人员的难题.本文简要分析了砌体结构温度裂缝的成因,并介绍了温度裂缝理论研究方面的进展以及目前国内外温度裂缝控制的设计原则和措施,在讨论了我国这方面工作仍然存在的主要不足的基础上,指出今后对砌体结构温度裂缝的研究的主要方向.  相似文献   

5.
对砌体结构温度裂缝的易发部位和引起裂缝的原因进行了简要分析,提出了砌体结构伸缩缝间距超限后的设计措施,并结合工程实例给予了论述.  相似文献   

6.
砌体结构温度裂缝问题及其处理   总被引:2,自引:0,他引:2  
胡昌胜  王刘洋 《工程与建设》2006,20(4):309-310,312
由于钢筋混凝土和砖砌体的线膨胀系数和收缩率不同,在温度应力的作用下,砌体结构建筑物常会出现大量的温度裂缝,影响建筑物的安全性和耐久性。针对砌体结构温度裂缝的主要特征,分析了温度裂缝的主要类型及其产生原因,提出在设计阶段和施工过程中采取相应的技术措施进行处理,防止和减轻温度裂缝的出现。  相似文献   

7.
为探讨砌体结构温度裂缝机理,对一砌体结构墙体与屋面板的温度场进行了实测,得到了砌体结构墙体与屋面板随时间的温度分布,给出了砌体结构建筑温度场的变化规律,在实测温度场的基础上,用有限元法对整体结构进行了温度应力分析,并给出了考虑干缩影响的温度应力计算方法.研究结果为控制砌体结构温度裂缝提供了参考.  相似文献   

8.
分析了砌体结构房屋温度裂缝产生的原因,提出了设计中存在的问题及温度裂缝的预防措施。  相似文献   

9.
本文对砌体结构产生温度裂缝的主要原因进行、分析,针对性提出了砌体结构裂缝控制的建议性措施,并对今后解决裂缝问题及对策提出意见。  相似文献   

10.
这些年,我国建筑业发展较快,砌体结构在整个建筑业中主要部分。砌体结构温度裂缝这一质量通病也就成了建筑业迫切需要解决的重要问题,砌体结构温度裂缝不但影响建筑物的外观,同时也影响建筑物的使用寿命及使用功能。  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.
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   

13.
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   

14.
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   

15.
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   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
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   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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