【作者】 杨艳青；

【导师】 贺少辉；

【作者基本信息】 北京交通大学 ， 地下工程， 2012， 博士

【摘要】 运营隧道作为铁路运营线路上的重要基础设施,其技术状态直接影响着铁路行车安全。因隧道衬砌先天不足而造成的缺陷,以及因运营逐渐劣化而形成的病害,都在严重降低衬砌结构承载力安全储备,缩短其剩余寿命,进而影响隧道的正常使用。然而,目前对于隧道技术状态,尤其是衬砌结构剩余寿命的评估方面尚缺乏全面深入的研究。本文采用有效的调查、检测手段获取影响运营隧道衬砌结构的主要技术参数,运用合理的评估模型,对衬砌结构剩余寿命给出合理评价,为运营隧道的维修养护和新建隧道工程设计提供理论参考。1、运营铁路隧道衬砌结构安全性检算方法研究研究了影响运营隧道衬砌结构安全性的隧道荷载类型和取值,衬砌结构尺寸、材料性能,以及结构计算模型等因素,提出以运营隧道实际技术状态为依据的衬砌结构安全性检算方法,并通过算例验证其合理性。与拟建隧道工程计算方法相比,该方法更具有针对性,得出的计算结果更符合运营隧道的实际情况。2、运营铁路隧道安全性评定研究在总结吸收国内外研究成果的基础上,采用实际调查与理论研究相结合的方法,对我国铁路运营隧道管理的现状进行分析,基于运营铁路隧道安全信息表征,归纳总结出影响隧道安全性的七个主要参数,并通过相应指标对主要参数划分等级,提出定性和定量相结合的多指标、多参数运营隧道安全性评定模型和方法。为了获得较为合理的评价结果,将隧道衬砌安全性评价指标划分为三个层次,应用模糊数学理论,提出了运营铁路隧道衬砌安全性三级模糊综合评价方法,并通过工程实例举例说明该方法的评价过程。计算结果表明,采用此方法得到的评价结果与基于经验判断的评价方法相吻合,证明了此评价方法的可行性和合理性。3、运营隧道衬砌结构剩余寿命评估模型研究以铁路隧道混凝土整体式衬砌为研究对象,全面分析了影响隧道衬砌结构剩余寿命的诸多因素,包括衬砌与围岩之间的接触状态、围岩状态劣化、衬砌裂损、渗漏水及冻害、衬砌材料劣化、计算模型等,建立起基于荷载-结构模型的运营隧道衬砌结构剩余寿命评估模型。该模型以衬砌混凝土强度为可变参数,结合隧道衬砌结构当前状况计算衬砌结构内力,采用破损阶段法求出衬砌各截面安全系数,并以三截面破坏作为衬砌结构剩余寿命终结的标准,最终确定其剩余寿命。评估模型充分发挥了隧道衬砌承载力,较好地反映了各主要影响因素,符合运营隧道的实际情况。同时,通过算例分析可知,病害的存在会大大降低衬砌结构承载力安全储备,缩短其剩余寿命。给出衬砌结构剩余寿命评估流程,重点分析了评估模型主要参数的获取方法。衬砌结构几何尺寸和衬砌与围岩之间的接触状态可采用隧道限界量测方法结合地质雷达法获得。衬砌混凝土材料特性,尤其是混凝土强度检测需要通过大量室内试验、无损检测来获得。围岩状态的检测包括围岩及衬砌背后回填料的材料特性、围岩松动高度(围岩压力)等的检测,需要进行室内试验、原位测试和地质雷达法检测确定。衬砌结构裂损、渗漏水及冻害等衬砌病害需进行现场调查和观测,病害较严重时,需要对衬砌裂损的范围及发展情况、水压力、围岩冻胀力等进行量测和检测。4、铁路隧道衬砌状态地质雷达检测模拟试验研究以我国单线铁路隧道常见的模筑混凝土整体式衬砌和复合式衬砌为研究对象,建立衬砌试件和隧底模型,并在模型中设置衬砌背后空洞、回填不密实等工况类型,进行地质雷达检测模拟试验。试验结果表明,地质雷达检测可反映出试验中预设的各种工况类型,可识别衬砌试件及隧底模型中各介质层层位,并能够定量分析出其厚度。地质雷达法是检测隧道衬砌结构尺寸及衬砌与围岩接触状态的目前尚可利用的有效方法之一。更多还原

【Abstract】 The operation tunnels are critical infrastructure on the railway lines, and the technology of the operating tunnel directly impacts the traffic safety. Both defects caused by deficiencies, such as construction quality and construction error, and diseases due to the long-term operation can reduce the safety stock of the lining bearing capacity, shorten its residual life, and are serious threat to the use of the tunnel. Currently, there is lack of research on the operating tunnel technology, especially the assessment of residual life of the tunnel lining. In this paper, the main technical parameters which affect the lining operation are obtained by effective investigation and detection, and reasonable model is built to assess the residual life of the lining structure. This will have important reference value for the repair and maintenance of the operating tunnel and the design of the new tunnel engineering.Study on calculation method of structure safety of operating railway liningThe factors which affect the safety of the tunnel lining are deeply studied, such as the tunnel load types and values, the lining structure dimensions and material properties, structural calculation model, and so on. Then the calculation method based on the actual technical state of the operating tunnel is put forward, and its legitimacy is verified by a numerical example. The calculation results obtained by this method compared with the results by the proposed tunnel project are more targeted, and more similar to the actual situation of the operating tunnel.Study on safety evaluation of operating railway tunnelsReferring to the research results from home and abroad, as well as adopting the research methods integrating theory with practice, the current situation of the operation and management on the railway tunnels was analysed, and seven main parameters was summarized. The parameters were graduated by correspondence indexes. And then the model and method of indexes and parameters which were combined in qualitative and quantitative was set up. The model of safety evaluation of the operation railway tunnels was based on expression and indication for safety information of operation tunnel. In order to obtain more reasonable assessment results, all the indexes are divided into three levels, and the three-level fuzzy synthetic evaluation method for the safety of the operating railway tunnel is proposed in accordance with the fuzzy mathematics theory. Furthermore, the evaluation process by means of this method is illustrated by an engineering example. The results show that the evaluation results obtained by means of this method is correspondent with the results by the evaluation method based on empirical judgments, which proves that this evaluation method is feasible and reasonable.Study on assessment model of residual life of lining structureIn this paper, the integral lining of the railway tunnel is chosen as the study object. The factors which affect the residual life of the tunnel lining are studied, such as the contact state between the lining and the surrounding rock, deterioration state of the surrounding rock, the lining dehiscence, leakage water and frost damage, deterioration of the lining materials, computational model and so on, and the assessment model of the residual life of lining structure is established according to the load-structural model. In this assessment model, the lining concrete strength is chosen as variable parameter, and the lining structural internal force is calculated combined with the current status of the lining. Then the lining safety factors of each cross-section are calculated by means of the plastic stage design method. Besides, the damage of three cross-sections is considered as the standards of the end of the residual life of the lining structure. Finally, the residual life of the lining is determined. The assessment model makes good use of the bearing capacity of the tunnel lining, and better reflect the actual situation of the operating tunnel. A numerical example shows that the lining diseases will greatly reduce the safety stock of the lining carrying capacity and reduce residual life of the lining.The evaluation process of the residual life of the lining structure is shown, and the acquisition method of the main parameters of the assessment model is studied. The geometric dimensions of lining structure and the contact state between the lining and the surrounding rock can be obtained by tunnel clearance measurement combined with ground penetrating radar (GPR). Lining concrete material properties, especially concrete strength can be obtained through a large number of laboratory tests and nondestructive tests. The state of the surrounding rock including the material properties of the surrounding rock and the backfill behind the lining, the surrounding rock loose height (rock pressure) detection, can be obtained by laboratory tests, in situ testing and GPR detection. Lining structure breakage, leakage water and frost damage can be gained by field investigations and observations, and the scope and development of the lining crack, water pressure, the surrounding rock frost heaving force should be considered when the lining diseases are more serious.Simulation test of GPR detection of railway lining state The integral lining and composite lining which are the common-mode on single-track railway are chosen to be studied, and lining specimen and the model of the tunnel bottom are built, where the type of working conditions including the empty behind the lining, uncompacted backfill are set. Then GPR detection simulation test is performed. The test results show that the GPR detection can reflect the types of working conditions pre-set in the test, and identify dielectric layers in the model, whose thickness can be quantitative analysed. GPR detection is an effective way to detect geometric dimensions of lining structure and the contact state between lining and surrounding rock.更多还原