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1.
突水突泥灾害是岩溶隧道施工中经常面对的严峻挑战.综合采用地震方法和电磁方法对阳灵隧道F_1断裂带开展了超前地质预报,准确地预报了充填溶洞的位置和规模.突泥事故治理过程中,首先采取稳定塌落体、封堵下泄口和加固已有支护等措施控制灾情;然后利用三台阶法和双层钢拱架支护通过了溶洞影响段;最后,采用地质雷达探测了溶洞规模和充填情况,并对围岩和支护结构的受力变形状况进行监测.结果表明,综合超前地质预报是探测隧道不良地质体的有效途径,"控制灾情,谨慎开挖,事后监控,确保安全"是突泥事故治理的合理原则.  相似文献   

2.
通过采用长期预报和短期预报相结合的方式,准确预报尚家湾强岩溶隧道突水突泥伴生灾害源的规模与空间位置,结合超前钻探建立综合超前预报体系。针对发生的3次突水突泥灾害,通过现场踏勘和水文地质分析,查明突水突泥伴生灾害源的来源,揭示尚家湾隧道突涌灾害源的赋存特征、致灾模式及其致灾机理,提出突涌灾害是由压力水、泥砂相结合的伴生灾害源和突涌通道2部分组成,伴生灾害源是内在源动力,突涌通道是灾害源的优势运移路径。同时,建立集内外结合(隧道内部揭露围岩与地表环境)、综合预报、"循环推进,交叉评价"、动态补探、综合治理相结合的伴生灾害源探测及防治技术,提出相应的治理原则、治理方案及后续施工的预防措施。  相似文献   

3.
在隧道施工过程中,因隐伏于岩体中的含水构造系统被揭露破坏,很可能导致开挖临空面与导水通道进行连通,从而发生突水突泥灾害。通过建立充填介质滑移失稳力学模型并利用有限差分模拟软件模拟岩溶管道在不同水压力影响下隧道发生突水突泥的可能性,研究了复杂地质条件下隧道突水突泥的致灾机理。结果可供隧道施工参考。  相似文献   

4.
为研究富水全强风化花岗岩隧道突水突泥灾害机制与帷幕注浆技术,以广西均昌隧道富水全强风化花岗岩地段突水突泥灾害处治实践为例,对隧道突水水泥灾害特征、诱发机制及防治措施进行深入研究分析。结果表明:富水全强风化花岗岩隧道突水突泥灾害突发性强,演变速度快,次生灾害严重,影响范围大;隧道突水突泥灾害的孕险环境因素有长条状谷地汇水负地形、水资源丰富、导水通道发育、岩层水稳定性差,而超前勘探工作不充分、注浆效果不到位及施工扰动是灾害的主要致灾因子,岩体受地下水浸泡软化,岩层在静水压力作用下被击穿,掌子面发生局部渗流失稳,形成突水通道,渗流转变为管道流,形成突泥通道,在静水压力和动水冲刷的共同作用下迅速演化发展成突水突泥灾害,同时引发地表塌陷、河流断流、池塘干涸等次生灾害;通过修正帷幕注浆参数,隧道注浆治理段开挖面整体稳定性显著增强,稳定渗流量减少53.78%~80.19%,对隧道堵水加固效果明显,能有效防治了突水突泥灾害,确保工程施工安全,缩短建设工期,增大工程效益。研究成果对全强风化花岗岩隧道防治突水突泥灾害具有一定指导意义。  相似文献   

5.
主要介绍宜万铁路大支坪隧道DK133+990岩溶异常体水文地质特征、岩溶发育规模、高压富水溶腔突水突泥经过及特点,并根据溶洞工程、水文地质条件及历次突水突泥机理,综合考虑施工及运营安全等多种因素,遵循“释能降压、注浆加固、超前支护、综合治理”的原则进行溶洞治理。  相似文献   

6.
盾构隧道穿越溶洞密布的复杂环境时,不可避免的引起岩溶开挖区应力场突变,严重时造成溶洞坍塌、隧道突水突泥等工程灾害.采用有限元模拟方法,基于岩层破坏机理,分别针对溶洞数量不同及排列方式不同这两种重要因素,从隧道开挖引起的位移场、应力场和塑性区域三个方面分析岩溶隧道开挖所引起的围岩变化规律.结果表明:溶洞的存在使得隧道围岩最大主应力显著提高,围岩竖向位移随溶洞个数增加而增大,围岩周围土体的应力场、位移场、塑性区域均随着洞-隧之间不同的排列方式而呈现不同的变化规律.分析结果可为岩溶地区盾构隧道设计、施工以及运营提供理论及工程指导.  相似文献   

7.
为实现对岩溶隧道安全性的快速评价,采用统计与理论分析相结合的方法,针对岩溶隧道突水突泥灾害的灾害源和防突结构,选取水动力条件、不良地质、防突厚度及围岩特征这4个方面因素,建立一种适用于工程现场的突水突泥快速判识方法即岩溶隧道突水突泥防突评判方法(PSAM法),构建突水突泥防突评判影响因素指标体系,即以防突厚度、水压力特征、不良地质、岩体质量和完整性为主要影响因素,围岩节理状态、水源补给条件、水力连通性、岩石强度为次要影响因素,岩层走向与倾角、地应力、岩体透水性特征为修正因素,提出各影响因素的分类方法和等级划分体系,形成适用于工程现场快速查询与评判的影响因素分级与评分表,阐述防突评判实施流程。将该评判方法应用于宜万(湖北宜昌—重庆万县)铁路野三关隧道"602溶腔"大型突水突泥灾害工程。研究结果表明:该评判方法克服了现有突水突泥风险评价不能描述防突结构围岩特征及厚度影响作用的不足以及传统最小安全厚度计算方法针对孕险环境和围岩特征等重要影响因素考虑不全面的欠缺;工程应用结果验证了该评判方法的科学性和实用性。  相似文献   

8.
目的分析多场耦合作用下海底岩溶隧道稳定性.方法建立基于Hoek-Brown准则的岩体弹塑性损伤-渗流耦合模型,通过ABAQUS软件中Umat子程序接口实现了模型的有限元计算,利用该模型对大连海底岩溶隧道进行数值计算.结果溶洞作用下地表沉降曲线在开挖面中线两侧存在较大差异,随着上覆海水压力的增加,沉降最大值出现小幅增长,其位置逐渐向溶洞中线处偏移;当施加充填水压时,地表沉降值、开挖面附近围岩位移值和衬砌最大主应力值均发生明显变化;随着充填水压的加载,隔水岩体的损伤值和损伤区域逐渐增大,渗透系数成数量级增长,形成的导水通道为开挖面发生突水突泥灾害埋下了隐患.结论计算结果对岩溶区隧道监测和突水灾害防治具有指导意义.  相似文献   

9.
岩溶隧道施工遭遇岩溶特别是充填(水、黏土)岩溶,极易发生涌突水、涌突泥灾并引发隧道冒顶、地表水源流失等地质灾害及地表生态环境破坏问题,轻则影响工期,重则对洞内施工人员和机械设备造成危害.研究岩溶隧道穿越位置岩溶发育及其充填性质,总结隧道施工岩溶灾害处理经验,无疑对今后西南岩溶隧道施工具有重要的指导意义.以云南某高速公路隧道为例,对季节变动带岩溶发育分布规律、岩溶灾害治理进行了初步探讨.  相似文献   

10.
为有效识别隧道突水突泥致灾构造,基于致灾构造的地质特征、地球物理响应特征和钻探揭露特征,提出了一种集地质识别、物探识别、钻探识别为一体的隧道突水突泥致灾构造综合识别方法,阐述了其实施流程和实施原则.地质识别提供先验信息,指导物探的实施和解译,物探指导钻探施工,地质、物探、钻探有机结合与相互印证,识别过程动态反馈.给出了断层和岩溶突水突泥致灾构造的发育规律、地质特征和突水突泥灾害前兆地质信息,不同物探方法下的地球物理响应特征及钻探揭露特征,指导隧道施工过程中致灾构造的识别.利万高速齐岳山隧道实践证明,该方法可有效识别致灾构造的空间位置分布特征,可为同类工程隧道突水突泥致灾构造的识别提供参考和借鉴.  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.
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 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   

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.
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   

18.
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   

19.
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   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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