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1.
根据岩体结构特点,建立了节理岩体的无单元模型,编制了二维节理岩体的无单元程序,并给出了算例。计算结果表明,该模型是合理可行的。  相似文献   

2.
无单元法应用于节理岩体   总被引:1,自引:0,他引:1  
无单元法是一种新方法,其在岩体问题的应用中,至今报道甚少.根据岩体结构特点和无单元法的优点,建立了节理岩体的二维无单元模型,编制了相应的节理岩体无单元程序,并给出了算例,计算结果表明,该模型是合理可行的,同时给处理岩体节理问题带来了方便.  相似文献   

3.
基于PFC中FISH语言,采用双线性锚杆本构模型对岩体加锚节理面在剪切荷载作用下的力学行为进行数值模拟研究,通过变化锚杆刚度和浆体强度,深入研究岩体结构面-浆体-锚杆相互作用下锚固体系宏细观力学响应。结果表明:加锚节理面的力学响应与锚固结构的力学性质密切相关。锚杆刚度越大,节理面宏观抗剪强度越高;随着锚杆刚度的增加,岩体和浆体中的裂纹也越来越多,锚杆对浆体和岩体的损伤逐渐增加。岩体结构面-浆体-锚杆相互作用,裂纹的产生首先起于节理面上和锚杆与节理面交叉处,随着剪切位移的不断增加,节理面上的裂纹在接触力集中的地方继续产生,而在锚杆周围则由锚杆与节理面交叉处向锚杆两端继续扩展,且裂纹集中在锚固体系的受压侧,主要为由"压致拉"机理导致的张拉裂纹。浆体的强度过小或过大都可能导致锚固体系中裂纹数量的增多,且裂纹以张拉裂纹为主。当浆体强度较低时,裂纹主要集中在浆体中,而当浆体强度较高时,裂纹主要集中在岩体中。因此,在对节理岩体进行加固的过程中,应综合考虑节理面宏观上的抗剪强度和细观上锚固体系的损伤,以实现锚固体系的宏细观耦合支护。分析结论对于节理岩体的锚固支护设计具有参照价值。  相似文献   

4.
利用界面元法来研究岩体中的不连续问题是非常有效的。文章研究了节理岩体作为复合块体的等效模型,建立了包含层状节理的复合界面元分析模型,并研究了包含锚杆界面的加锚岩体复合界面元非线性分析模型;针对锚杆所穿越节理面有可能相接触和张开2种情形,分析了锚杆在节理面的抗剪作用机理,导出了相应的弹塑性矩阵。给出的算例表明该法是适用有效的。  相似文献   

5.
采用正交数值模拟方法研究了岩体及注浆体相关因素对节理化岩体注浆锚杆基础抗拔力的影响.数值模型中考虑了岩石弹性模量、浆体弹性模量、节理迹长、节理倾角、锚杆埋深5个因素的变化,选择5因素4水平的正交试验方法进行了数值模拟.结果表明,锚杆埋深对注浆锚杆基础抗拔力的影响最大,其次为浆体弹性模量、岩石弹性模量、节理迹长、节理倾角,浆体弹性模量和强度对锚杆基础抗拔力的影响虽然大于岩石弹性模量的影响,但是提高浆体强度和弹性模量对节理化岩体注浆锚杆基础抗拔力的提升效果有限.  相似文献   

6.
为了研究锚杆加固节理岩体的锚固机理,借助颗粒离散元软件PFC2D软件内嵌FISH语言分析了加载过程中锚杆和结构面之间的相互作用机理以及锚杆内部轴向和剪切应力情况,探讨了锚杆对结构面锚固效应和锚杆的变形破坏规律。结果表明:锚杆在剪切荷载作用下容易在结构面和锚杆交界位置发生"S"形变形并在节理面两侧形成塑性铰,导致锚杆在塑性铰处发生拉弯屈服,揭示了锚杆在剪切作用下的拉弯屈服机制,并从细观机制上阐明了锚杆对岩体结构面的支护作用主要体现为结构面内聚力的提高。  相似文献   

7.
针对波兰煤矿地下开采中的锚杆支护应用实践,提出了统一的采矿地质和技术条件的评价方法,用修RMR岩体量化指数从给定公式中确定岩体强度和应变参数。基于虎克-布朗强度准则给出了岩体及顶板锚固的数值模型。在不同的采矿地质条件下,进行了多种顶板锚固应用研究。这些支护实验表明:这种方法应用于巷道的初次支护和顶板加强支护是安全可靠的。  相似文献   

8.
节理岩体中隧洞的破坏模式与节理属性密切相关.基于一个能描述多组节理的岩体模型,采用数值模拟技术研究了节理倾角和侧压力系数对节理岩体中隧洞破坏模式的影响结果表明,节理岩体中隧洞的破坏模式受节理倾角控制.在较小节理倾角下,主要表现为肩部岩体的弯曲断裂、节理之间的分离和边墙岩体的压碎;在较大的节理倾角下,主要以边墙岩体的压碎和节理之间层状岩体的滑移为主侧压力系数亦影响隧洞破坏模式,在较小的侧压力系数下,隧洞破坏主要受节理倾角影响;随着侧压力系数的增大,其破坏主要受构造应力影响.这些结论可为隧洞支护设计和施工提供参考  相似文献   

9.
带软弱结构面岩体的弹性有限元分析   总被引:3,自引:0,他引:3  
通过分析指出,用近似于矩形或长方体的常规实体单元描述平面或空间岩体问题中的软件弱结构面,春精度比简化的节理单元或夹层单元要高。在计算效率上,由于简化的节理单元或夹层单元的劲度矩阵元素与常规实体单元相同,因而简化的节理单元中夹层单元并无优越性,对岩体中软弱结构面的描述可采用常规的实体单元而无需进行特殊处理。  相似文献   

10.
由康德尔提出来的个体单元法,是巷道周围不连续性岩体结构的数值解之一。本文介绍了一个尝试,即:用个体单元法摸清不连续性岩体和块体井壁结构的破坏过程,以及锚杆支架的支护效果。对个体单元法的基本原理也做了介绍。与模型实验方法相比,个体单元法具有不少优点。  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 Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
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   

15.
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   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
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   

20.
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   

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