Visual Measurement Device and Experiment of Ground Water Level in Vacuum Preloading
Due to the inaccuracy and incapability of the conventional methods of monitoring the groundwater level in vacuum preloading, a visual apparatus of the measuring groundwater level has been designed. The proposed visual apparatus was efficiently developed based on the video camera technology. Utilizing a video camera system, it could be transmitted to the location of the groundwater level in real time to the image receiver. This paper proposes a novel approach using the visual measurement device and assess the conventional methods for performing ground improvement in an area located in Lianyungang, China. The groundwater level, vacuum pressure and the shear strength of soil were recorded during the vacuum consolidation process. Since groundwater level varied in vacuum consolidation, it would be necessary to analyze and assess the variation of shear strength of soil caused by changing the groundwater level. The results showed that the proposed approach is more reliable and intuitive than conventional methods in order to measure the groundwater level under vacuum preloading. Eventually, it is worth mentioning that, the shear strength of soft soil was different at above and below the groundwater level.
KeywordsGroundwater level Shear strength Vacuum preloading
This work was supported by the national natural science foundation of China (Grant No. U1134207 and 51408187) and the program for new century excellent talents in university (Grant No. NCET-12-0843).
- 1.Rujikiatkamjorn, C., Indraratna, B.: Environmental sustainability of soft soil improvement via vacuum and surcharge preloading. In: Proceedings of the 2014 Geo-Congress, pp. 3658–3665. ASCE, Atlanta (2014)Google Scholar
- 3.Griffin, H., O’Kelly, B.C.: Sustainability of combined vacuum and surcharge preloading. In: Proceedings of the 2014 Geo-Congress, pp. 3826–3835. ASCE, Atlanta (2014)Google Scholar
- 4.Yan, L.: Soft Soil Reinforced by Vacuum Method of Preloading, 2nd edn. China Communications Press, Beijing (2013)Google Scholar
- 5.Gao, Z.W., Hou, J.F., Liang, A.H.: Analysis and test method for groundwater level by vacuum preloading. Chin. J. Geotech. Eng. 35(s2), 684–688 (2013). (in Chinese)Google Scholar
- 6.Liu, H.L., Zhou, Q., Gu, C.C.: New method for measuring groundwater under vacuum preloading. Chin. J. Geotech. Eng. 31(1), 48–51 (2009). (in Chinese)Google Scholar
- 7.Zhang, G.X., Dong, Z.L., et al.: Discussion and improvement of underground water level measurement technology in vacuum preloading. Rock Soil Mech. 28(9), 1899–1903 (2007). (in Chinese)Google Scholar
- 8.Li, P., Jin, Y.T., et al.: Review of research on characteristics of seepage-induced consolidation of soil under negative-pressure reinforcement conditions. J. Hohai Univ. (Nat. Sci.) 44(02), 115–121 (2016). (in Chinese)Google Scholar
- 9.Li, P., Liu, W., et al.: Visual measurement device for underground water level under negative pressure condition and measurement method: China, CN104316144A (2015). (in Chinese)Google Scholar
- 10.Bao, S.F., Mo, H., Dong, Z.L., Chen, P.S.: Increment calculation of soil shear strength for sand drain foundations consolidation groundwater level. Chin. J. Rock Mech. Eng. 33(6), 1269–1277 (2014). (in Chinese)Google Scholar
- 11.Lai, J.Y., Li, P., Tang, J.H.: An apparatus for measuring groundwater level under negative pressure and experimental investigation. China Harb. Eng. 37(11), 35–39 (2017). (in Chinese)Google Scholar