Study of Deep Drain Stability in High Steep Slope: Fid-Bau Portal

Study of Deep Drain Stability in High Steep Slope

Qin, Zhibin / Zha, Xudong

The seepage situation of cutting slope groundwater is simulated and analyzed with the finite element software ANSYS. Comparing and analyzing the seepage field distribution of setup plan for hole diameter, hole long, hole distance to different drainage holes, it gets that the incidence and effect for changes of hole diameter, long hole, hole distance to drainage seepage field distribution. Combined with the real project, it discusses the distribution of slope seepage field under drainage holes laying double row along elevation, and draws that drainage holes laying multi-row along elevation can significantly improve drainage effect. So it determines the design project for drainage curtain of water-rich and high-steep cutting slope. Then, through the geological prospecting and the hydrological conditions survey in the real engineering, combined with the results of drainage pipes with finite element analysis, the specific buried project of deep drainage pipes is identified. Moreover, according characteristics of deep drainage, the technology and the control requirements of corresponding construction are established. Finally, slope surface deformation and internal displacement are monitored by using GPS and inclinometer. Monitoring results for many times in 18 months are analyzed. The largest surface deformation is 41.4 mm, and the largest internal deformation is only 10 mm, all are less than the first order of allowing deformation 123.75 mm of 0.0025h (h is the height of slope). Slope stability is got, and it is further validated the slope has a good stability after the deep drainage treating.