Stabilization of deep seated movement in a Saprolitic Massif supporting a highway viaduct

Stabilization of major soil masses using drainage tunnels

“…This case history is described in detail by Wolle et al (2004) and is considered by the authors a landmark in Brazil. For this reason, in this item a summarized version is presented.…”

“…Main advantages of this drainage solution are: • Groundwater lowering through predominantly vertical flow, conceptually eliminating / reducing significantly destabilizing seepage forces; • Use of gravity flow, eliminating the necessity of energy supply and long-term maintenance of pumping systems; • No need of any activity, including construction, inside the unstable soil mass; • No impact on the surface and risk of damage to the stabilizing system through vandalism. Stabilization of unstable or failed soil masses through drainage tunnels has been used in several locations around the world, with case histories presented, from different locations, in Europe (for example, Bardanis & Cavounidis, 2016;Bertola & Beatrizzotti, 1997;Eberhardt et al, 2007;Marinos & Hoek, 2006;Futai et al, 2009), in the Americas (Rico & Castillo, 1974;Vargas, 1966;Wolle et al, 2004;Yassuda, 1988), Asia (JLS, 2002;Lin et al, 2016;Sun et al, 2009;Wang et al, 2013;Wei et al, 2019;Yan et al, 2019), and Oceania (Gillon & Saul, 1996).…”

“…Figure 6 above shows that for the stabilization of the landslide in Cubatão, several tunnels (galleries) were excavated and drains were drilled from these galleries. Figure 8 below shows the drainage tunnel and its adits used to stabilize the VA-19 landslide, published by Wolle et al (2004). A single access tunnel was excavated from an adequately located position at the surface, under the unstable ground mass; adits were built from the tunnel alignment to optimize drainage and tunnel length.…”

“…The plan view of the tunnel built to stabilize the VA-19 landslide (Wolle et al, 2004), presented in Fig. 8, shows also that a single tunnel would be much less effective than the system of adits and tunnels built.…”

Estabilização de encostas através de drenagem profunda: estudo de um caso de estabilização com túnel de drenagem.

“…Alguns casos de estabilização de encostas, em que foi utilizada drenagem profunda em São Paulo são: o escorregamento da massa de tálus (massa coluvionar) junto à Usina Henry Borden, no município de Cubatão (Vargas, 1966); o escorregamento da massa de tálus na cota 500 da Via Anchieta (Teixeira & Kanji, 1970); a movimentação da encosta na qual está implantado o viaduto VA-19 da Rodovia dos Imigrantes (Wolle et al, 2004), dentre outros.…”