Experimental Study on Karst Roadbed of Expressway Reinforced by Root Piles

Yuchao Xia, Dongyan Liu, Yuming Lu, Xiaofeng Tuo, Jie Shen
To explore the reliability of karst roadbed of expressway reinforced by root piles, a field load test was conducted at a typical karst roadbed section, through which the bearing capacity features of single root pile and features as well as intensity parameter of bearing capacity of soil foundation between root piles were collected. Secondly, the construction of reinforced karst roadbed was numerically simulated and analyzed. Research demonstrated that: the field load test confirms bearing
more » ... firms bearing capacity of both single root pile and composite foundation satisfying the engineering design standard; grouting liquid during the root pile construction improves the shearing strength of soil between root piles significantly. The cohesion c is improved by 1.75 times and the internal friction angle φ is increased by 1.45 times; the numerical simulation of embankment construction confirms the effectiveness of root piles in reinforcing soft karst roadbed, controlling karst collapse and settlement deformation after embankment construction, and improving the stability of bank slope. These research results provide test basis and instructions on the application of root piles in karst roadbed treatment of expressway.