【作者】 王琦；

【导师】 李术才； 唐春安；

【作者基本信息】 山东大学 ， 岩土工程， 2012， 博士

【摘要】 煤炭开采进一步向超千米深井发展是我国煤炭行业发展的必然趋势,而厚煤层开采又是煤炭深井开采的一个重要内容。巨野矿区深部厚顶煤开采中暴露出的各种问题对我国此类巷道支护提出了更高的要求。深部厚顶煤巷道两帮及顶板均为软弱煤体,开挖以后易出现较大范围的破裂区,顶板煤体碎胀严重,极易与基本顶产生明显离层,顶板下沉量大,且持续变形,给巷道围岩控制带来极大困难。目前,有关深部厚顶煤巷道围岩变形破坏及稳定性控制机理方面的研究还很少,且在现有的巷道支护体系中,适合此类巷道经济有效的支护手段还很欠缺。因此,从根本上认识深部厚顶煤巷道的围岩变形破坏机理,提出合理的支护对策,对我国深部厚煤层开采具有重要的理论与现实意义。本文以巨野矿区典型的深井煤矿-赵楼煤矿为工程背景,针对深部高地应力作用下厚顶煤巷道支护难题,通过现场实测、理论分析、材料研发、数值分析、模型试验及现场试验等手段相结合的方法,对深部厚顶煤巷道的变形破坏及围岩控制机理进行研究,并研发出适用于该类巷道支护的让压型锚索箱梁支护系统。本文进行的主要工作及创新点如下：1.深部厚顶煤巷道变形破坏规律现场实测研究。对赵楼煤矿深部厚顶煤巷道水文地质、地应力、岩石物理力学性质等工程地质条件及原支护条件下矿压、围岩变形破坏与支护构件受力状态等进行现场监测研究。通过研究分析得到赵楼煤矿深部厚顶煤巷道顶板围岩碎胀变形严重、离层量大、变形持久不可控的主要原因及机制。2.厚顶煤巷道顶板冒落机理研究。基于塑性力学的极限分析理论,采用广义Hoek-Brown经验强度准则,考虑了巷道顶板围岩应力与支护荷载的作用,推导出了巷道顶板冒落的迹线方程,讨论了不同岩体力学参数、围岩应力水平与支护荷载大小对顶板冒落范围的影响。对赵楼煤矿3302工作面深部厚顶煤矩形巷道进行了算例分析,研究了支护载荷对顶板冒落范围的影响,并根据工程实践,提出了相应的工程技术措施。3.让压型锚索箱梁支护系统研发。研究并提出了深部厚顶煤巷道“先控后让再抗”的耦合让压强力支护理念,研制了支护强度高、刚度大、预紧力损失小、具有定量让压性能、护表效果好且经济合理的让压型锚索箱梁支护系统。并根据托梁的不同布置方式设计了让压型锚索箱梁支护系统、工字钢锚索梁支护系统及T型钢带锚索梁支护系统、U型钢带锚索梁支护系统4大类14种试验方案进行对比研究。4.支护系统对比评价指标研究。通过研究提出了巷道表征变形量D、围岩控制经济指标I、支护系统组合构件整体性能利用率η、支护系统组合构件耦合效率W四个指标,利用层次分析法确定了巷道围岩变形权重值和支护系统组合构件耦合效率权重值。将上述指标用于巷道支护效果及支护系统组合构件耦合性能的对比评价,使评价工作得以量化。5.支护构件耦合性能数值研究。设计了不同支护构件及预紧力组合情况下的13种对比方案,通过数值试验统计分析,对各方案耦合性能进行对比研究。研究表明：耦合效果最好的3种计算方案分别为方案N3(Ⅱ12b+(?)22锚索)、方案N2(Ⅱ12a+(?)17.8锚索)和方案N5(Ⅱ12c+(?)22锚索)。同时分析了锚索型号与预紧力两因素对支护系统耦合性能和支护效果的影响。6.支护效果数值试验对比分析。14种支护方案数值试验结果表明：让压型锚索箱梁支护系统各方案比原支护方案效果显著提高；让压型锚索箱梁支护系统围岩控制效果整体优于工字钢锚索梁支护系统且经济性高；让压型锚索箱梁4种支护方案中,巷道围岩控制效果最好的为纵横组合方案,其次为纵向单梁方案,再次为纵向双梁方案,最后为横梁方案。7.现场支护构件新型监测手段与评价系统现场应用。研发、制作并在现场试验中应用了测力箱梁、测力工字钢和测力钢带,用于支护构件的受力监测。利用建立的评价系统对现场试验得到的围岩收敛、顶板离层、顶板弯曲沉降、围岩深部位移、锚杆与锚索托锚力、钢梁与钢带受力等监测结果进行综合对比分析,对不同方案优劣进行了量化综合评定。8.多方案现场试验对比研究。针对3302工作面顺槽特点,结合理论分析与数值试验结论提出了不同支护系统及其方案的选取原则,并按该原则进行了3大类11种方案的现场试验研究。在每个支护方案试验段设置多个监测测站,通过监测结果综合对比分析得到了与理论分析及数值试验基本一致的结论。让压型锚索箱梁支护系统各方案围岩控制效果整体优于工字钢锚索梁支护系统,明显优于原方案,其中纵横组合方案效果最好,其次为纵向单梁方案。经综合分析给出了在地质条件恶劣的厚顶煤巷道支护时,首选让压型锚索箱梁支护系统纵横组合方案；当地质条件稍好时,选用让压型锚索箱梁支护系统纵向单梁方案的工程建议。9.柔性加载系统研发。针对目前地质力学模型试验加载边界条件存在的问题,基于对多类特种柔性橡胶材料进行的研究,结合试验要求,研制出新型柔性均布压力加载装置,并用于本文模型试验研究,使加载系统更真实的满足对原型条件的模拟要求。10.地质力学模型试验对比研究。基于赵楼煤矿深部厚顶煤巷道工程地质条件,对两种典型支护方案下的3302工作面顺槽开挖支护过程进行了地质力学模型试验研究。试验采用了光纤光栅和电阻应变测试系统、光栅多点位移数据采集系统、数字照相系统和新型支护构件受力监测系统等监测手段；得到了不同支护方案的巷道围岩应力演化规律、围岩变形规律及支护构件的受力特性。结果表明纵向单梁方案支护效果总体优于横梁支护方案。11.锚索梁支护系统作用机制研究。建立了锚索梁支护系统对顶板围岩作用的三维力学模型,通过理论分析和推导得到锚索梁及其不同布置方式、锚杆、锚索单独或联合作用下的顶板围岩围压计算公式。利用该公式,对锚索梁支护系统不同布置方式作用下的顶板围岩应力状态进行算例分析,结果显示：纵横组合方案在顶板围岩中形成的围压状态最佳,其次为纵向单梁方案,纵向双梁方案及横梁方案分列其后。将理论计算、数值试验与现场试验结果进行综合对比分析,得到了锚索梁支护系统的作用机制。更多还原

【Abstract】 The coal mining are developing towards over1000m is an inevitable trend of mining industry in China. The thick coal mining is an important part of deep coal mining. The problem, which was exposed in deep mining with thick top-coal of Juye mining area, proposes higher demand to support these kinds of roadways in China.For the roof and two sides of deep roadway with thick top-coal are soft coal, its easy to apear large range of fratured zone; roof coal breaking and expanding seriously, easily separated from the basic roof; and the roof has large and lasting deformation, all of the above problems bring huge difficulty to control the surrounding rocks of roadway. At present, little study has been carried on for the defomiation failure and stability control mechanism of surrounding rock in deep roadways with thick top-coal. Among existing roadway support systems, economic and efficient support methods are deficient which suitable to these roadways. Therefore, fundamentally recognizing the deformation failure mechanism of surrounding rock in deep roadways with thick top-coal, and proposing reasonable support solution, is of important theoretical and practical meaning for deep and thick coal mining in China.Taking typical deep coal mine of Zhaolou in Juye mining area as engineering background, aiming at the difficult support of deep roadways with thick top-coal under high ground stress, methods of field measurement, theoretical analysis, material development, numerical analysis, model test and field test was combined to research deformation failure and control mechanism of surrounding rock in deep roadways with thick top-coal. Pressure relief anchor box beam (PRABB) support system that suitable for these roadways was therefore been developed. The main work and innovative points are list as follows:1. Field measurement study on deformation and destruction law of deep roadways with thick top-coal. Field monitor research was carried out on the engineering geological conditions of deep roadways with thick top-coal in Zhaolou mine, such as hydrologic geology, geostress and physical-mechanical properties of rock, as well as the mine pressure, the deformation and failure of surrounding rock, the stress state of support units under conditions of original supporting program. The main reason and mechanism were obtained from these researches and analysis, which of serious bulking deformation, great bed separation amount and uncontrollable lasting deformation on the roof and surrounding rock of deep roadways with thick top-coal in Zhaolou coal mine.2. Mechanism research on roof carving in deep roadways with thick top-coal. Based on the limit analysis theory, adopted generalized Hoek-Brown experience strength rule, and considered the effect of strain level and support load of roof and surrounding rock in roadways, the roof carving trace equation was deduced. Meanwhile, the effect to the range of roof carving was discussed, which caused by mechanic parameters of different rocks, strain level of surrounding rocks and support load. Calculation example analysis was carried out on the deep rectangular roadways with thick top-coal in3302work face of Zhaolou coal mine, and the effect to the range of roof carving which caused by support load has been researched. Meanwhile, engineering technology measure has also been put forward according to the engineering practice.3. The research and development of pressure relief anchor box beam(PRABB) support system. The support concept of high strength coupling pressure relief was put forward, which is first anti-pressure, second pressure relief, and third anti-pressure. The PRABB support system was developed, which has high strength support pressure, better bending stiffness, lower pre-tightening force loss, quantitative pressure relief, good supporting surface effect and reasonable economic. Fourteen test schemes with different arrange modes were designed, classifying into four kinds of PRABB support system, I-steel anchor beams support system, T-steel strip anchor beams support system and U-steel anchor beams support system.4. The evaluation index research on the contrast of support systems. In the research, four indexes were proposed, which of roadway characterization deformation D, the economic index of surrounding rock control I, the whole performance utilization ratio of support system combined units η and the combined units coupling ratio of support system W. By the use of hierarchy analytical method, the deformation weight value of surrounding rock in roadways and coupling ratio weight value of support system combined units were determined. The above indexes were used in the contrastive evaluation of the combined components coupling performance of support system and roadway support effect, and therefore the contrastive evaluation can be quantification.5. Numerical research on coupling performance of support members. Thirteen contrastive schemes were designed with different combination of support members and pre-stressing. By means of the statistical analysis of numerical test on these schemes, contrastive research was carried out on the coupling performance of each scheme. Results show that the top three schemes with best coupling effect are scheme N3(Ⅱ12b+(?)22anchor), scheme N2(Ⅱ12a+(?)17.8anchor) and scheme N5(Ⅱ12c+(?)22anchor). Meanwhile, the two factors of anchor type and pre-pressure were analized, which has affected coupling performance and support effect of the support systems.6. Contrastive analysis of support effect numerical test. As the support effect analysis of the numerical test on the fourteen support schemes show, the support effect of PRABB support scheme was dramatically enhanced than by original scheme; the PRABB support system has advantage than I-steel anchor beams support system on the support effect and economic; among the four support scheme of PRABB, cross and longitudinal combination scheme was best in surrounding rock controlling, longitudinal single anchor beam scheme was lest best, and then longitudinal double anchor beam scheme, cross anchor beam program was relatively poor.7. The field application of new monitoring methods and evaluation system of field support components. Force-measuring box beam, force-measuring I-steel beam and force-measuring steel strip were developed and applied in the field test, to monitor the force on the support components. By use of the established evaluation system, integrating contrastive analysis has been carried out on the monitoring results of surrounding rock convergence, roof abscission layer, bending settlementof roof, deep displacement of surrounding rock, anchor rod acting force, the force on the pad of anchor, steel beam steel strip acting force in the field test and make quantitative comprehensive evaluation of the superiority and inferiority of different schemes.8. Contrastive research field test with multi-schemes. Considered the characteristic of3302working face crosshead, combining with theoretical analysis and numerical test results, the choosing rule of support scheme was put forward, which guided the field test research of eleven schemes classified into three kinds. Many monitoring station were set up on the test section for each support scheme, the conclusion which obtained from the integrating contrastive analysis on monitoring result was almost the same with the theoretical analysis and numerical test. All schemes with PRABB were better than I-steel scheme, and had dramatically advantage than original support scheme. Among the schemes of PRABB, longitudinal and cross combination scheme has the best effect, longitudinal single anchor beam scheme been lest best. Meanwhile, the engineering advices after integrative analysis was proposed, which is foist choose longitudinal and cross combination scheme of PRABB under harsh geological conditions, and choosing longitudinal single anchor beam scheme when the geological conditions is better.9. Develop of flexible load system. Considering the existing load boundary condition problems of geomechanics model test, based on the research of various kinds of special flexible rubber materials, combined the test requirement, the new flexible uniform distributed pressure load device was developed and used in the model test, which was better stimulate original condition more actual.10. Contrastive research of geomechanics model test. Based on the engineering geological condition of deep roadways with thick top-coal in Zhaolou coal mine, the geomechanics model test research was carried out on the excavation and support process of3302wording face crossheading. Advanced monitoring methods were adopted which include fiber grating and resistance strain test system, grating multi-point extensometer measurement and data collection system, digital photography system and new force monitoring system of support component. Meanwhile, the strain evolution law of surrounding rocks with different support schemes, surrounding rocks deformation law and the force character of support units were obtained. The test results show that longitudinal single beam scheme has better support effect than cross beam scheme, which is consistent with field rule.11. Function mechanism research of anchor beams support system.3D mechanics model was set up, which simulate the anchor beams support system acting on roof and surrounding rocks. From theoretical analysis and derivation, the confining pressure calculation formula of roof and surrounding rocks was obtained, which is according to different arrangement modes of anchor beams, cables and anchors act alone or combined. By means of the formula, analysis of examples on the strain statement of roof and surrounding rocks in different arrangement modes of anchor beams support system, the result shows that:the confining pressure statement caused by cross and longitudinal combination scheme was the best, longitudinal single beam scheme was lest better, longitudinal double beams scheme and cross beam scheme were relatively poor. From the integrative and contrastive analysis of the results obtained from theoretical calculation, numerical test and field test, function mechanism of anchor beams support system was obtained.更多还原