A structural health assessment method for shield tunnels based on torsional wave speed

来源 :Science China(Technological Sciences) | 被引量 : 0次 | 上传用户:wjyjiedabc
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Following recent rapid developments in tunnel engineering in China,the heavy structural maintenance work of the future is likely to pose a great challenge.Newly developed vibration-based health assessment and monitoring methods offer good prospects for large-scale structural monitoring,hidden surface detection and disease pre-judgment.However,because the dynamic properties of tunnels are sensitive to the coupling and damping effects of the surrounding soil,there is little relevant research on tunnel structures.Using the PiP(pipe in pipe)model,the intrinsic tunnel modes and their response characteristics are investigated in this paper,and the degree to which the identification of these characteristics is influenced by mode superposition and the soil coupling effect are also considered.The response features of these flexible wave modes are found to be barely recognizable in a tunnel-soil coupled system,while the phase velocity of the torsional wave can be determined by combining phase spectrum analysis and the HHT(Hilbert-Huang transformation)method.A new structural health assessment method based on the torsional wave speed is therefore proposed.In this method,the torsional wave speed is used to determine the tunnel structure’s global stiffness based on a newly developed dispersion algorithm.The calculated stiffness is then used to evaluate the tunnel’s structural service status.A field test was also carried out at a newly built tunnel to validate the proposed method;the tunnel structure’s Young’s modulus was obtained and was very close to the designed value.This indicates that this method is an effective way to assess tunnel service conditions,and also provides a theoretical basis for future applications to health assessment of shield tunnels. Following recent rapid developments in tunnel engineering in China, the heavy structural maintenance work of the future is likely to pose a great challenge. Newly developed vibration-based health assessment and monitoring methods offer good prospects for large-scale structural monitoring, hidden surface detection and Because the dynamic properties of tunnels are sensitive to the coupling and damping effects of the surrounding soil, there is little relevant research on tunnel structures. Using the PiP (pipe in pipe) model, the intrinsic tunnel modes and their response characteristics are investigated in this paper, and the degree to which the identification of these characteristics is influenced by mode superposition and the soil coupling effect are also considered. The response features of these flexible wave modes are found to be barely recognizable in a tunnel -soil coupled system, while the phase velocity of the torsional wave can be determined by combining phase sp ectrum analysis and the HHT (Hilbert-Huang transformation) method. A new structural health assessment method based on the torsional wave speed is assumed. In this method, the torsional wave speed is used to determine the tunnel structure’s global stiffness based on newly developed dispersion algorithm. The calculated stiffness is then used to evaluate the tunnel’s structural service status. A field test was also carried out at a newly built tunnel to validate the proposed method; the tunnel structure’s Young’s modulus was obtained and was very close to the designed value. This indicates that this method is an effective way to assess tunnel service conditions, and also provides a theoretical basis for future applications to health assessment of shield tunnels.
其他文献
早在十九世纪Jaeger(1854)Von Graefe(1854)Weber(1855)等即发现了青光眼性视乳头凹陷,其后Muller(1855)从病理组织学证实了青光眼性视乳头凹陷。自此以后许多学者研究了慢
Coats在1908年将有大片渗出的视网膜病分三型:第一型血管无异常;第二型血管有异常;第三型动静脉吻合。后者尔后称为视网膜血管瘤。Leber(1912)报告3例第二型Coats病,并称为
近十五年来,在视网膜色素变性这一类疾病的遗传、视网膜的功能特性和代谢等各方面,从各个研究领域都取得了不少的新成果。兹就以下各方面分别叙述。一、临床方面视网膜色素
近年来,小儿厌食症的发病率比较高,笔者于1998年1月~1999年1月应用儿康宁治疗60例,取得较好疗效,现报道如下。1临床资料1.1一般资料:选择3~8岁患儿60例,其中男32例,女28例,平均年龄5.2岁。均按小儿厌食症的诊疗标准
自从成为一名教师,我便一直担任班主任,多年的工作经验,使我对班主任工作的认识愈发深刻,在工作中也能够做到游刃有余,更是得到了许多教师的认可。在他们的眼里,似乎什么样的
An artificial water curtain system is composed of a network of underground galleries and horizontal boreholes drilled from these galleries.Pre-grouting measures
近二十多年来,眼科学有了较大的发展。在基础理论方面,目前国外设有专门的研究机构,从事眼胚胎、遗传、组织解剖、病理、生理、生化、微生物、药理、免疫学等方面的研究。许
介绍了超低铂CB -8半再生重整催化剂在石家庄炼油厂的工业应用情况。该重整催化剂在石炼累计运行1910天 ,共再生5次 ,催化剂寿命达86.83m3/kg。工业应用表明 ,该催化剂是一种
患儿 女,4岁。因反复发热、盗汗、纳差半年,腹部隐痛2d2000年2月15日入院。体查:体温37℃,轻度贫血貌,心、肺正常。腹平软,肝于右肋缘下05cm,剑突下1cm可触及,质软,无压痛,脾未触
一辆金杯双排座货车因发动机不能起动,到我厂修理。据驾驶员说,只因白金烧了,换了一副新的之后,发动机就再也起动不着了。检查后确认:化油器里有油,白金间隙基本正确,高压火