Analysis of the field behavior of a geosynthetic reinforced soil integrated bridge system during construction and operation
Date
2016
Authors
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Journal ISSN
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Publisher
University of Delaware
Abstract
The Geosynthetic Reinforced Soil Integrated Bridge System (GRS-IBS) is a composite bridge structure built using GRS abutments and prefabricated bridge superstructure elements. This accelerated bridge construction technology has been developed and promoted by researchers and engineers from the United States of America’s Federal Highway Administration (FHWA). GRS-IBS technology has proven itself useful for rapid, cost-effective bridge construction in other regions of the United States. Consequently, the Delaware Department of Transportation (DelDOT) constructed the first GRS-IBS in the state of Delaware (Br. 1-366) in 2013 to explore the effectiveness of this technology for use within their own bridge inventory. ☐ This dissertation provides an overview of the design, construction, and monitoring process that was utilized to deploy the first constructed GRS-IBS in Delaware. Recorded performance data for the structure from the time of construction, live load testing, and over two years of in-service operation were collected using different types of instruments and analyzed. ☐ Details regarding GRS-IBS technology, Br. 1-366 project requirements, the design and construction procedure, and the instrumentation system that was utilized for monitoring the health of the structure have been presented in Chapters 1 through 3. ☐ The collected engineering data from different phases of the project are presented in Chapter 4, including construction, live load testing, and over two years of in-service operation. ☐ Since the amount of collected data was quite large, some techniques were utilized to manage and filter the recorded data, as described in Chapter 5. A technique for statistical correlation analysis is also presented in this chapter, which was found to be very useful for developing an understanding of interrelationships between various sensor measured values. The correlation between different types of readings are investigated using this technique, and the corresponding findings from this analysis are presented in this chapter. ☐ A strong effect of temperature on the measured strain readings was observed, as discussed in Chapter 5. Chapter 6 presents a correction procedure to account for the effects of temperature on the measured strain values. The use of this correction technique allows for significant refinement of the measured strain values within the GRS abutment. ☐ The details and findings from a robust live load testing program are presented in Chapter 7. More specifically, the effect of the live load on the strain in the abutments and the pressure within and beneath the abutments have been investigated in this chapter. It is shown that the structure was quite stable during each of the live load test events, with the induced pressure and deformation by the live loads being quite low, and with little corresponding strain being measured within the GRS abutments. ☐ The applied pressure distribution beneath the west GRS abutment foundation was investigated during construction and live load testing, as described in Chapter 8. It is shown that the pressure distribution is not uniform and the maximum pressure is measured beneath the facing wall. An approach is suggested in this chapter to predict the applied pressure induced by the abutment and the surcharge loads. ☐ The long term performance of the structure is analyzed in Chapter 9 using the data collected by different sensors over two years of in-service operation. The data analysis shows the effect of the precipitation amount and type (rain and snow) on the abutment water content. The abutment performance that occurs as a result of changes in water content appears satisfactory. Creep deformation did occur in the abutment, but its overall magnitude was quite small over the monitoring period, with the maximum strain being less than 0.5%. The lateral deflection and settlement of the facing walls was small, less than 12 mm. The concrete bridge deformation was also small, with the measured results being affected by the air temperature change. The abutment temperature distribution was different in hot and cold weather. The clay foundation beneath the abutment experienced some minor creep deformation. The results also indicated the effect of temperature on the measured foundation and abutment pressure. ☐ Finally, the overall conclusions of this dissertation are presented in Chapter 10 and some recommendations are made for future research.