Experimental Research of Excavation Disturbance Effect Due to Trenchless Construction by Using Distributed Strain Sensin
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ORIGINAL PAPER
Experimental Research of Excavation Disturbance Effect Due to Trenchless Construction by Using Distributed Strain Sensing Technique Yue Li . Ge Song . Jing Cai
Received: 31 August 2017 / Accepted: 13 May 2020 Ó Springer Nature Switzerland AG 2020
Abstract In this paper, an assessment method of excavation disturbance effect is proposed by using distributed optical-fiber strain sensing technique. Model tests of trenchless construction under different parameter conditions are carried out in the laboratory. In the test, the excavation was simulated by using the deflate of pre-burying air bag, soil displacement is measured by settlement mark, at the same time, The soil strain of overburden layer is obtained based on Brillouin Optical Time-Domain Analysis (BOTDA). Through the analysis of the experimental data, the partition theory of excavation disturbance zone is proved and verified through test data. The correlation between ground settlement and soil strain distribution due to trenchless construction are compared and analyzed. The mechanical response of overlying pavement are further discussed. Research results indicate that soil strain of overburden layer is symmetrically distributed about the excavation surface, which is compressed near the centerline and tensioned on both sides due to the excavation disturbance impact. The width of excavation disturbance Y. Li (&) G. Song J. Cai College of Airport Engineering, Civil Aviation University of China, Tianjin, People’s Republic of China e-mail: [email protected] G. Song e-mail: [email protected] J. Cai e-mail: [email protected]
zone derived from the test data shows good accordance with the calculation results based on the partition theory, the maximum error is less than 10%. A certain consistency exists between the distribution law of strain curve and settlement trough. Due to the uneven distribution of support force caused by foundation settlement, the pavement model shows notable bending deflection after trenchless excavation, and the maximum increment ratio of support force exceed 50%. The combined impact of ground traffic load and excavation disturbance is considered to be more unfavorable to the safety of pavement structure. The conclusions can be suggestive and helpful to trenchless excavation control. Keywords Trenchless construction Excavation disturbance effect Brillouin Optical Time-Domain Analysis Optical fiber
1 Introduction In recent years, trenchless technology has been widely used in the construction projects of pipeline installation under highway and airport pavements, since this method has less impact on the ground displacement and traffic disruption, compared with traditional cutand-cover methods (Marzouk et al. 2010). However, the control conditions are extremely complex, so that excavation disturbance effect is inevitable. Invisible
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Geotech Geol Eng
underground movement and deformation of soil may lead to foundation collapse and ground loss, which is a potential ha
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