本文選題：多道瞬態(tài)瑞雷波探測　切入點：道間時差相位　出處：《中國地質大學(北京)》2017年碩士論文

【摘要】：自20世紀70年代以來,瑞雷波探測方法在工程中逐步得到認可和應用,目前,多道瞬態(tài)瑞雷波勘探已經成為工程中較為常用的物探方法之一。囿于波動問題空間采樣率觀念的限制,現(xiàn)有多道瞬態(tài)瑞雷波探測方法采用小道間距、多道檢波器排列方式觀測同一次激發(fā)的瞬態(tài)瑞雷波,雖然解決了同時觀測不同頻率成分波動的問題,但一個排列的多道檢波器只能得到一條瑞雷波相速度—探測深度曲線,工作效率和橫向分辨力受到極大限制。另外,對于瑞雷波相速度成像的波速分級,一直以來都沒有形成一個固定的參考標準,這使得對瑞雷波探測結果的解譯具有很大的主觀性和局限性,同時,現(xiàn)有瑞雷波成像結果主要表達二維的剖面圖,這中表達方式很難去直觀、準確地揭示工程巖體中巖溶構造等不良地質體的規(guī)模、空間分布和連通狀態(tài)。本文針對現(xiàn)有方法的弱點,對瞬態(tài)瑞雷波相速度的提取及其探測結果成像進行了研究,得到了以下三點認識:(1)提出了考慮道間時差相位的瞬態(tài)瑞雷波相速度提取的理論方法,形成了解算多道瞬態(tài)瑞雷波探測深度的新技術,這種方法突破了傳統(tǒng)采樣定理的要求,擺脫了現(xiàn)有方法道間距對頻率成分的束縛,只用兩道檢波器的瞬態(tài)瑞雷波記錄即可提取多種頻率成分波動的相速度,完成現(xiàn)有方法一個多道檢波器排列才能完成的工作,大大提高了探測的工作效率和橫向分辨力。(2)提出了瑞雷波相速度分級方案,通過對場地及其周邊的巖土體試樣進行波速測試,建立了瑞雷波相速度分級與巖土體及巖溶破碎帶性狀的對應關系,為工程巖體瑞雷波相速度成像奠定了物理基礎。(3)利用實測獲取的工程巖體瑞雷波相速度的空間分布數(shù)據(jù),依托于貴陽地鐵巖溶洞穴探測項目研究建立的瑞雷波相速度與工程巖體性狀對應的瑞雷波相速度分級方案,以沿測線的瑞雷波相速度—深度成像剖面和不同深度的瑞雷波相速度成像水平切片按照剖面和切片的空間位置組合,實現(xiàn)了工程巖體瑞雷波相速度空間分布的三維可視化;從瑞雷波相速度三維可視化空間展布圖中,可以直觀地看出巖溶破碎帶的尺度大小、空間位置和連通狀態(tài)。這種利用瑞雷波相速度空間數(shù)據(jù)構建瑞雷波相速度三維成像,直觀、準確地揭示工程巖體中巖溶構造的規(guī)模、空間分布和連通狀態(tài)的探測成果,在工程中尚無先例。這一探測方法在位于強巖溶富水區(qū)的貴陽地鐵工程巖體巖溶探測中應用,探測結果與施工揭露的巖溶實際情況非常吻合,驗證了方法的合理性和正確性,為地鐵工程巖溶病害治理提供了有力的技術支撐。
[Abstract]:Since the 1970s, Rayleigh wave detection methods have been gradually recognized and applied in engineering. Multi-channel transient Rayleigh wave exploration has become one of the commonly used geophysical prospecting methods in engineering. Due to the limitation of spatial sampling rate concept of wave problem, the existing multi-channel transient Rayleigh wave detection methods adopt small track spacing. The transient Rayleigh waves excited by the same excitation are observed by the arrangement of multichannel geophone. Although the problem of simultaneously observing the fluctuation of different frequency components is solved, only one Rayleigh wave phase velocities and detection depth curves can be obtained by an arranged multichannel geophone. Working efficiency and lateral resolution are greatly restricted. In addition, there has been no fixed reference standard for Rayleigh wave phase velocity classification. This makes the interpretation of Rayleigh wave detection results very subjective and limited. At the same time, the existing Rayleigh wave imaging results mainly express two-dimensional profile, which is difficult to be intuitionistic. The scale, spatial distribution and connected state of poor geological bodies such as karst structures in engineering rock mass are accurately revealed. In this paper, the phase velocity extraction of transient Rayleigh waves and the imaging results of the transient Rayleigh waves are studied in view of the weakness of the existing methods. A theoretical method of phase velocity extraction of transient Rayleigh waves considering the phase of time difference between tracks is proposed, which forms a new technique for calculating the detection depth of multi-channel transient Rayleigh waves. This method breaks through the requirements of the traditional sampling theorem. In order to get rid of the restriction of channel spacing on frequency component, the phase velocity of frequency fluctuation can be extracted only by the transient Rayleigh wave record of two geophone, and the work of a multichannel detector arrangement can be accomplished by the existing method. The Rayleigh wave phase velocity classification scheme is proposed, which is used to measure the wave velocity of rock and soil samples in and around the site. The corresponding relationship between Rayleigh wave phase velocity classification and the characteristics of rock, soil and karst fracture zone is established, which lays a physical foundation for Rayleigh wave phase velocity imaging of engineering rock mass. Based on the research of Guiyang metro karst cave exploration project, the Rayleigh wave phase velocity classification scheme corresponding to the characteristics of engineering rock mass is established. The 3D visualization of Rayleigh wave phase velocity distribution in engineering rock mass is realized by combining the Rayleigh wave phase velocimetry profile along the line and the Rayleigh wave phase velocity imaging horizontal section of different depths according to the spatial position of the section and slice. From the 3D visualization space layout of Rayleigh wave phase velocity, the size, spatial position and connected state of karst broken zone can be seen intuitively. This kind of 3D image of Rayleigh wave phase velocity is intuitively constructed by using Rayleigh wave phase velocity spatial data. There is no precedent to reveal the scale, spatial distribution and connected state of karst structure in engineering rock mass accurately. This method is applied in karst detection of Guiyang metro engineering rock mass in strong karst and rich water area. The results of detection are in good agreement with the actual situation of karst exposed by construction, which verifies the rationality and correctness of the method and provides a strong technical support for the treatment of karst diseases in subway engineering.
【學位授予單位】：中國地質大學(北京)
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：P631.4
，

本文編號：1660966