岩石冻融循环特性试验与低温响应数值模拟研究

发布时间：2018-03-18 11:11

本文选题：冻融循环　切入点：岩石试验　出处：《中国地质大学（北京）》2013年硕士论文　论文类型：学位论文

【摘要】：我国是世界上多年冻土分布面积最多的国家之一。随着西部大开发和振兴东北战略的实施，对冻土的研究逐步深入，采用一般冻土力学方法去研究冻岩问题，已难满足日益增长的工程需要。因此，将冻岩问题作为一门新的研究方向提出来是必要的。冻岩的主要工程危害有岩质边坡的冻融剥蚀、滑塌以至滑坡，隧道岩体的冻胀开裂、失稳，路基及建筑地基由于冻融产生的岩石底板冻胀抬升和融化下沉，输油气管线围岩的冻胀使得管道挤压开裂，，液化天然气储存库岩腔冻胀影响储存罐的安全等。目前，研究者研究了冻结对寒区隧道的影响，也对冻胀力对渠道的破坏进行了研究，但对冻结对寒区岩质边坡的影响的研究尚不多见。论文以“青藏铁路沿线地质灾害发育规律及致灾机理研究”为背景，开展如下研究工作：（1）选取工程常见岩性岩石（砂岩、灰岩、花岗岩），加工成标准试件，进行饱和状态下冻融循环试验，冻融温度区间为-20℃～+20℃。观察岩石破坏物理过程，测定试样冻融循环下的尺寸、质量、超声波波速；对不同循环次数下的花岗岩进行单轴抗压试验。同时，取标准试件制作时保留的砂岩和灰岩的岩屑，同步进行冻融试验，每隔5次循环取出部分碎屑进行电镜扫描试验，研究冻融循环下岩石微观结构变化特性。（2）通过分析冻融循环试验测定物理力学参数，分析冻融破坏形式、试件变形、波速变化规律；岩石不同冻融次数后的抗压强度变化，分析岩石经过冻融后物理力学特性变化；分析0、5、10、15次冻融循环岩石碎屑电镜扫描照片，分析岩石微观损伤规律；总结岩石冻融损伤影响因素。（3）以冻土理论为基础，研究低温岩体多场耦合等效分析方法。在研究的基础上，建立边坡等效模型，分析不同温度边界对边坡的温度场、位移、应力场的影响。
[Abstract]:China is one of the world's most populous country in Permafrost Distribution area. With the implementation of the western development and the revitalization of Northeast China strategy, the research on frozen soil is gradually thorough, the frozen soil mechanics method to study the problem of frozen rock, has been difficult to meet the growing needs of the project. Therefore, the problem of frozen rock as a new study the direction proposed is necessary.
The main works of frozen rock damage freeze-thaw erosion with rock slope, collapse and landslide, frost cracking, tunnel rock instability, roadbed and construction of foundation due to freeze-thaw of rock bottom frost uplift and thaw settlement, frost heave of oil and gas pipeline rock make the extrusion cracking of pipelines, liquefied natural gas storage in rock cavity heaving influence storage tank safety. At present, the researchers studied the effect of freezing on the tunnel in cold region, also made a study of frost heave force on the channel, but the effect of cold and freezing rock slope is still rare. Under the background of "the laws of development and disaster mechanism research" the geological disasters along the Qinghai Tibet railway, to carry out research work as follows:
(1) selection of engineering rocks (sandstone, limestone, granite), processed into standard test pieces of saturated freeze-thaw cycle test, freeze-thaw temperature range of -20 to +20 DEG C. To observe the damage of rock physical process, determination of freeze-thaw cycle size, quality of ultrasonic wave; uniaxial compressive tests of different cycles under granite. At the same time, the standard test pieces retained when making sandstone and limestone debris, synchronous freeze-thaw test every 5 cycles to remove part of debris SEM experiment research on freeze-thaw cycle of rock microstructure change characteristics.
(2) through the analysis of physical and mechanical parameters determination of freezing and thawing test, failure mode analysis of freezing and thawing, specimen deformation, velocity changes; compressive strength of rock after different freeze-thaw times, analysis of rock physical and mechanical properties change after freezing thawing; 0,5,10,15 analysis of freeze-thaw cycles of rock debris SEM photograph, analysis of rock the micro damage law; summarize rock freeze-thaw damage factors.
(3) based on frozen soil theory, the equivalent analysis method of multi field coupling for cryogenic rock mass is studied. Based on the research, an equivalent model of slope is established, and the influence of different temperature boundary on temperature field, displacement and stress field of slope is analyzed.

【学位授予单位】：中国地质大学（北京）
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU45

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