芒洪八角塔基础及塔身无损探测的研究

发布时间：2018-05-23 19:51

本文选题：瑞雷波 + 探地雷达　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：塔是一种在亚洲常见的,有着特定形式和风格的中国传统建筑。最初是供奉或收藏佛骨、佛像、佛经、僧人遗体等的高耸型点式建筑。处于少数民族聚集区的云南芒洪八角塔是全国重要保护文物,集佛教、儒家和道教与一身的建筑更是绝无仅有。然而如今八角塔年久失修塔身向北倾斜,塔体也出现了开裂现象。为了防止八角塔在重力作用下继续倾斜,迫切需要利用一种不会对塔身塔基造成伤害的探测办法,能针对八角塔的内部裂缝以及塔基不牢固的问题进行无损探测,以便后期修缮工作的开展。探地雷达和瑞雷面波探测由于其高分辨率、高效率以及不对探测目标构成损伤等特点,故被已诸多被用于地基的掩埋部分以及建筑物本体固结情况的探测。本文首先利用探地雷达的高分辨率特性对塔体内部损伤和裂缝进行探测;进而利用瑞雷面波分析近地表速度结构,对塔基周围地层的探测,结合工程地质信息,推断塔身倾斜的原因,为保护文物和后期修缮提供依据。本文以八角塔为研究对象,通过在塔基四周开展探地雷达扫描以及瑞雷面波的采集,获取了塔基周围的岩土信息以及塔身的裂缝信息,具体完成了以下研究工作:一、在八角塔周围布置了四条相互垂直的测线,利用重锤激发的方式采集了地震资料。在各相同测线上分别利用400MHz、900MHz的雷达天线进行了扫描,并在近塔基附近布设了三条环绕八角塔的八边形探地雷达测线,完成了诸多实测资料的采集。二、对采集到的两种资料进行了有效的资料处理工作,成功去除了干扰波以及背景噪声。对探地雷达资料进行了偏移处理,绕射波收敛效果较好,依据偏移剖面和地质背景资料,推断塔基应坐落于相对凸起的基岩面上。对地震资料进行了折射层析以及瑞雷波波速反演,推断出八角塔基础浅地表存在一米左右的回填土,且塔北侧存在的局部破碎带是导致塔向北倾斜的可能原因。结合八角塔旁开凿的探抗,验证了以上的一些推断。三、利用2GHz的雷达天线对八角塔塔身进行了扫描,绘制了裂缝的展布情况,并建立了三维裂缝发育模型。
[Abstract]:Tower is a traditional Chinese architecture that is common in Asia and has a specific form and style. It was originally a towering building dedicated to or collecting Buddhist bones, statues, sutras, Buddhist remains, etc. Yunnan Mannghong Octagonal Tower is an important protected cultural relic in the minority area, and the architecture of Buddhism, Confucianism and Taoism is unique. Now, however, the octagonal tower has been in disrepair and tilted northward, and the tower body has also been cracked. In order to prevent the octagonal tower from continuing to tilt under the action of gravity, there is an urgent need to use a detection method that does not cause damage to the tower's base, and can be used to detect the inner cracks of the octagonal tower and the problem of the instability of the tower's base. In order to carry out the later repair work. Ground penetrating radar (GPR) and Rayleigh surface wave detection (GPR) have been widely used in the detection of the buried part of the ground and the consolidation of the building body because of its high resolution, high efficiency and no damage to the target. In this paper, the damage and crack inside the tower are detected by using the high resolution characteristic of ground penetrating radar, and then the near surface velocity structure is analyzed by Rayleigh wave, and the stratum around the tower is detected, which is combined with engineering geological information. The reason of tower tilting is inferred to provide basis for preservation of cultural relics and later restoration. Taking the octagonal tower as the research object, the geotechnical information around the tower foundation and the fracture information of the tower body are obtained by conducting the ground penetrating radar scanning and collecting the Rayleigh surface wave around the tower. The main works are as follows: first, four vertical lines are arranged around the octagonal tower, and the seismic data are collected by means of the hammer excitation. The radar antenna of 400MHz / 900MHz is used to scan the same measuring lines, and three octagonal ground penetrating radar lines around the octagonal tower are set up near the tower base. The acquisition of a lot of measured data has been completed. Secondly, the two kinds of data are processed effectively and the interference wave and background noise are removed successfully. Based on the migration processing of ground penetrating radar data, the convergent effect of diffraction wave is good. Based on the migration profile and geological background data, it is inferred that the tower base should be located on the relatively raised bedrock surface. Based on refraction tomography and Rayleigh wave velocity inversion of seismic data, it is inferred that there is a backfill of about one meter on the shallow surface of the foundation of the octagonal tower, and the partial fracture zone on the north side of the tower is the possible cause of the tower tilting northward. Some of the above inferences have been verified by combining the excavated reactance beside the octagonal tower. Thirdly, the 2GHz radar antenna is used to scan the octagonal tower body, and the distribution of cracks is plotted, and a three-dimensional fracture development model is established.
【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】：2017
【分类号】：TU317

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