Abstract: An accident involving the collapse of a running tunnel along Nanjing metro occurred when the tunneling shield arrived at the receiving shaft. Then vertical ground freezing was adopted to recover the collapsed tunnel. ...

Abstract: In this study, nano-SiO2 was synthesized using the sol-gel method to modify the properties of fly ash-slag geopolymers (FASGs). FASGs with six contents of sol-type nano-SiO2 (0, 0.1%, 0.2%, 0.3%, 0.4%, and 0.5%) and two ...