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1.
提高公路使用寿命,进行公路路面检测及养护已经成为公路养护部门刻不容缓的使命.分析当前公路沥青路面中出现的各种病害特征,着重介绍沥青路面弯沉检测技术、路面平整度检测技术、路面抗滑性检测技术、路面损坏状况检测技术的发展状况,探讨如何进行预防性公路养护的措施,客观而全面的论述如何开展公路路面维修治理工作,从而提高沥青公路的养护质量,方便车辆畅通无阻的运行.  相似文献   

2.
孙宏斌 《科技信息》2007,(24):120-120
一、概述随着公路建设的发展,沥青路面已成为我国公路路面的一种重要型式。但是由于忽视了结构设计,在已建成的沥青路面中,沥青路面不同程度地出现早期破坏现象,路面达不到《公路柔性路面设计规范》  相似文献   

3.
沥青路面是我国公路建设中常用的路面结构形式,其施工质量对公路行车安全性、舒适性有着重要的影响.同时路面施工质量还会影响路面排水的情况,关系到降水是否渗透造成路基稳定性降低情况的发生.本文针对沥青路面施工质量的重要性,对沥青路面施工管理工作重点进行了分析与论述.  相似文献   

4.
牟晋伟 《科技促进发展》2010,(4):135-135,127
公路沥青路面平整度问题是我国高等级公路建设普遍面临的问题之一。公路路面平整度是路面质量的重要控制指标,本文着重分析了影响公路沥青路面平整度的因素,并提出了提高沥青路面平整度的防范措施和对策。  相似文献   

5.
张霆 《科技信息》2010,(19):I0319-I0319,I0266
1微表处发展现状 在我国公路的路面结构中,沥青路面占主要位置,特别是高等级公路达90%,但随着公路交通量的加大,轴重的增加、交通的渠化等,一般的沥青路面就出现了严重地早期破坏如车辙、开裂、坑槽等,从而使路面使用寿命大大缩短,为此我国公路研究人员一方面从沥青路面结构入手进行研究,  相似文献   

6.
本文作者结合工程实践,指出了高速公路沥青路面平整度的影响因素和改善沥青路面平整度的施工措施。通过公路建设、养护的施工实践,探索分析了影响沥青混凝土路面平整度的因素,为公路沥青混凝土路面施工以及公路养护生产,保证路面平整度提供借鉴。  相似文献   

7.
针对目前中国日趋严重的超载现象,为方便公路养护管理部门定期对路面结构状况进行调查评定,及时对相应路段公路进行维修养护,以现行沥青路面设计规范为基础,经过大量的数据分析对比,利用线性回归方法,获得了车辆重载运输轴载作用下的沥青路面标准轴载换算公式;同时根据沥青路面结构特点,对考虑重载作用的路面结构的验算内容和原则进行讨论和分析,最终确定以考虑超载作用的路面弯沉值、容许拉应力值、路面使用寿命及所需结构层厚度,作为沥青路面结构承载力验算的验算系统。研究结果表明:得出的沥青路面标准轴载换算公式以及沥青路面结构验算系统,对国道G108陕西渭南故市镇路段路面结构状况的调查评定是合理的,评定结果可为公路养护部门提供科学的决策依据。  相似文献   

8.
杨斌 《甘肃科技》2010,26(11):146-147
如何提高公路沥青路面设计及施工质量,并将路面受雨水侵害降到最低,保证公路沥青路面的使用寿命和使用品质,要从设计、选材、施工、养护等各方面进行控制。  相似文献   

9.
黄伯宇 《科技信息》2008,(6):102-102
在中国经济强劲发展的带动下,公路建设也蓬勃发展起来。与此同时,公路建设中的一些问题也暴露出来。沥青路面是当前公路建设中使用较为普遍的面层铺装方式,新修公路的沥青路面过早的破坏,降低了公路的使用寿命,对新修公路的正常使用构成很大的威胁。下面通过沥青路面由于在路基施工、路面设计、路面施工、货车超载以及公路养护管理中存在的问题而导致的早期病害问题进行分析,并希望能够引起大家对这一问题的重视。  相似文献   

10.
袁伟涛 《科技信息》2012,(25):362-362,397
在我国北方地区,路面主要以半刚性基层的沥青路面为主,但是路面裂缝现象屡见不鲜,这不仅破坏路面连续性和平整性,影响行车舒适性,而且容易造成水损害,降低公路使用寿命。因此,科学分析、预防和处治沥青路面裂缝,是提高公路服务水平和延长公路使用寿命的关键。  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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