首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
为了分析金川深部巷道底臌形成过程以及支护对巷道稳定性的影响,运用声波单孔探测法,使用水做耦合剂,对巷道围岩松动圈进行测试。根据测出的深度-孔深曲线和各测孔漏水情况得出3个断面松动圈厚度以及围岩破碎程度。研究结果表明:初次支护设计对围岩松动圈有重要影响,巷道开挖支护一段时间后,松动圈厚度趋于稳定,返修后巷道围岩松动圈厚度不会有很大变化。巷道顶板和底角的围岩松动圈比两帮的厚,特别是底角处的松动圈较厚,在巷道两帮传递的集中应力的作用下,易发生破碎与移动,对于巷道围岩稳定性也有较大的影响。因此,使用锚索或者长度大于2.5 m的锚杆支护顶底角,对于延长巷道使用期限、减少返修周期具有重要意义。  相似文献   

2.
巷道围岩松动圈的大小是评定围岩稳定性和确定锚杆长度的重要依据,对双柳煤矿3306工作面回采巷道进行围岩松动圈测试,得出了该工作面松动圈范围。根据松动圈测试结果、巷道围岩松动圈支护理论及我国缓倾斜、倾斜煤层回采巷道围岩稳定性分类方案,最终确定了合理的巷道支护方式及参数,对类似地质条件下的巷道支护设计具有借鉴意义。  相似文献   

3.
在分析松软破碎带中巷道围岩的稳定性和支护影响因素的基础上,借助于注浆改善围岩特性并结合锚杆支护,通过现场实测、理论分析和FLAC数值模拟相结合的方法,确定了松软破碎带中的巷道围岩注浆深度、浆液比例和注浆孔间距等加固参数。研究结果对类似条件下的巷道的支护具有一定的指导意义。  相似文献   

4.
为解决深部破碎围岩巷道支护困难的问题,以卡斯特纳及基尔斯等理论为基础,着重考虑支护阻力对破碎围岩巷道应力分布规律的影响,建立非静水压力下圆形巷道围岩应力力学模型,并推导出围岩破碎区、塑性区的应力及影响范围的解析解,对比分析两者的不同侧压力系数与支护阻力的变化特征。针对不同区域内围岩破碎程度不同,提出先分层后整体支护、“锚网(索)+底板锚索+喷射混凝土+全断面注浆”修复方案。研究结果表明:巷道开挖后,围岩出现以纵向破坏为主的破坏形式,围岩破碎区和塑性区的环向应力均大于径向应力,且在破碎区、塑性区及弹性区的交界处均出现应力不连续现象;随着侧压力系数不断增大,破碎区与塑性区的半径随之增大,与塑性区半径的增长率相比,破碎区的半径增长率明显较大,围岩越来越趋于破碎;随着支护阻力增大,塑性区和破碎区的半径随之减小,但当支护阻力的强度达到一定强度后,破碎区和塑性区影响范围明显减小,说明支护阻力初期能够起到维持巷道稳定的作用,但一味地增加支护强度,只能增加支护成本,对围岩大变形控制效果十分有限;提出巷道支护向稳定控制转变,而不是强调变形控制;采用修复方案后,顶底板位移以及两帮位移都可以得到明显控制,说...  相似文献   

5.
为分析各种因素对深部软弱煤岩松动圈厚度的影响程度,选用原岩应力、巷道断面尺寸两个因素进行数值模拟,分析不同条件下煤岩松动圈厚度变化范围。在理论上定性分析深部开采煤岩松动破碎变形影响因素基础上,以数值模拟为主,定性分析松动圈破碎范围。根据理论分析矩形巷道基本变形规律,确定巷道围岩破坏规律,对深部开采煤岩松动破碎变形理论定性分析。确定影响煤岩松动破碎变形的主要因素,选择合适数值计算模型。根据数值模拟结果,分析每个方向的粘结力变化的临界点,然后确定其点的坐标值以绘制每个正交实验的松动圈,找出巷道围岩断面最易发生变形失稳的关键部位,分析规律性的结论。确定了不同截面情况下松动圈随巷道埋深及断面尺寸的变化趋势和变化速率,分析得出规律性的结论。  相似文献   

6.
利用松动圈原理确定锚杆支护参数的方法   总被引:4,自引:0,他引:4  
介绍了巷道(隧道)地下工程围岩松动圈支护理论并以此为依据确定了锚杆支护参数的方法.工程实践表明,用巷道围岩松动圈支护理论确定锚杆支护参数,支护效果好,又降低了工程造价,加快了施工速度,具有良好的推广价值.  相似文献   

7.
 为安全高效回采冬瓜山铜矿盘区隔离矿柱,在充分利用矿山已有巷道工程的前提下,仍需在盘区采场充填体下开挖新的出矿巷道.基于松动圈理论,利用单孔声波检测仪测量巷道围岩松动圈范围,为确定充填体下开挖巷道的顶板安全厚度、选择巷道支护方式提供依据.现场测试表明,冬瓜山铜矿-760和-790m巷道的围岩松动圈为0.8~1.3m.根据圣维南局部效应原理,结合工程技术人员的实际经验,最终确定采场充填体下新开挖出矿巷道的顶板安全厚度为4m.此外,通过松动圈测定和工程借鉴,确定新开挖巷道支护采用喷锚支护,局部破碎地方采用喷锚网联合支护,经理论计算和现场实测,总结出新开挖出矿巷道顶板锚杆长度选取2.2m、锚杆网度选取1.0m×1.0m时,能够安全经济地控制巷道松动圈.  相似文献   

8.
厚层破碎复合顶板巷道锚注支护技术   总被引:2,自引:0,他引:2  
破碎复合顶板裂隙极其发育,特别是厚层复合顶板厚度不稳定,个别地段存在泥质粉砂岩夹煤线厚度不稳定,导致其支护控制难度极大,成为影响煤矿安全生产的难题.小宝鼎煤矿在11391-1回风巷实施了综合机械化大断面掘进,掘进过程中,在锚网、锚索支护的基础上增加锚注支护,有效的控制了浅层破碎围岩离层,使破碎围岩顶板得到了有效地加固,改变了破碎围岩的松散结构,增强了浅部岩体的稳定性和整体强度.经过锚注支护,巷道自身形成承载结构,降低了围岩变形程度,将顸板下沉量控制在了合理范围,减少了巷道的维修量,节省了巷道维护成本.同时保证了施工的安全,加快了破碎围岩掘进工作面的推进速度.理论研究和工程实践成果指导该矿和相邻矿井安全生产有重要理论价值和借鉴意义.  相似文献   

9.
针对深部高应力破碎软岩巷道围岩变形量大、变形剧烈、底臌严重、流变性强、支护难等特点,基于巷道围岩松动圈地质雷达探测、收敛变形监测等地质力学测试技术,揭示深部高应力破碎软岩巷道变形破坏特征;采用数值模拟技术手段,从围岩强度特性、流变特性、巷道断面形状、软岩巷道群开挖相互影响、支护设计这5个方面分析深部高应力破碎软岩巷道变形破坏机理。针对安徽省淮南市朱集西矿深部开拓巷道特征与工程地质条件,提出"锚网索喷+U型钢支架+注浆+底板锚注"分步联合支护技术方案;基于大型三维模型试验系统,验证分步联合支护技术方案的可行性;采用FLAC 3D研究分析不同支护方案的支护效果,模拟验证分步联合支护方案的合理性。研究结果表明:分步联合支护技术方案有效地控制了深部高应力破碎软岩巷道的大变形与底臌,保证了巷道围岩与支护结构的长期稳定及安全。  相似文献   

10.
基于声波测试技术对金川二矿区深部巷道围岩松动圈进行了现场测试,通过对测试结果进行的分析和研究,得到了金川深部巷道围岩松动圈厚度的基本特征.借助FLAC3D数值分析程序建立了随机裂隙网络模型,分析了金川深部矿区巷道围岩塑性区发展规律.结合现场围岩变形收敛规律及支护体变形特征,基于喷锚网支护体与巷道围岩相互作用的力学机理,研究分析了金川深部巷道双层喷锚网支护结构的变形机制.  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号