A Simplified Approach for Evaluating Concrete Deterioration in Vertical Shaft Lining

2019

Xiaodong Zhao, China University of Mining and Technology; Guoqing Zhou, China University of Mining and Technology; Hengchang Liang, China University of Mining and Technology

This study describes the strain behavior in vertical shaft lining (VSL) embedded in thick soil deposits and its application in assessment of concrete deterioration. The observed strain in VSL continuously decreased companied by a sinusoidal fluctuation due to the influences derived from negative skin friction (NSF) and temperature. The increase in strain increment between peak and trough at each monitoring year and compressive strain level as the servicing time continued and VSL depth increased implies that the concrete strength was attenuated, and this attenuation was significantly dependent on the existing compressive strain level in VSL. The reliability of the proposed approach was validated by Schmidt Hammer Technique (SHT)–based concrete strength, and is applicable in concrete assessment and then fracturing prediction of VLSs in thick soil deposits.

Keywords: Field monitoring; strain behavior; concrete strength; VSL