## 4 Results
### Kinematic Assessment  
The main join sets are summarized in Table 1, which have been recognized in the geomechanical station (that is, an in situ geomechanical data and parameter observation  
Figure 4: Scheme of Punta Barbasquillo before (**a**) and after the slope failure (**c**). Image (**b**) shows the stereogram of the slope and main joint set. point) in the back analysis of the failed slope. The field strength of discontinuities (C, \(\varphi\)) was assessed using the Barton-Bandis [13; 14] criterion and in situ data (Schmidt hammer, JRC Barton's comb, etc.). An evaluation of the resistance of the joints has been proposed using parameters that can be obtained in the field without carrying out laboratory tests. For this reason, within the input of the Barton-Bandis criteria, a purely field methodology has been chosen to obtain the joint resistance and roughness. The two front faces of the slope as well as the main joint sets were represented using stereographic projection (Figures 5 and 6). The results of the kinematic assessment indicate that the slope was unstable. The instability can be observed in the joint S0 poles located inside the restricted daylight envelope (Figure 5). The toppling risk that could exist in the cliff before the planar failure was analyzed using projection (see Figure 7). The potential toppling of J2 towards the left (LS) and right (RS) sides of the cliff was also analyzed. The kinematic assessment shows a potential but not important risk: the pole of the joint J2 is not inside the daylight envelope but very close to the limit zone. The J2 should therefore be considered a tension crack. Once planar sliding has occurred, the new slope face overhanging the vertical could trigger both block and flexural toppling (Figure 7b), as can be concluded from the new and wider daylight pole envelope. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Join Set** & **Kind of Joint** & **Dip Dir (Degrees)** & **Dip (Degrees)** & **K Fisher Statistical** & **Joint Cohesion** \\  & & & & **Distribution** & **and Friction** \\ \hline S0 & Stratification-sliding surface & 004\({}^{\circ}\) & 36\({}^{\circ}\) & 106 & C = 0 \\ J1 & Joint & 264\({}^{\circ}\) & 88\({}^{\circ}\) & 2816 & \(\varphi\) =34\({}^{\circ}\) \\ J2 & Joint—tensión crack & 176\({}^{\circ}\) & 50\({}^{\circ}\) & 38 & \(\varphi\) =34\({}^{\circ}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Joint sets in the slope analyzed in Punta Barbasquillo. Figure 5: Stereographic representation of the joints and planes existing in the Barbasquillo slope using DIPS software [16]. Figure 6: Process to design the restricted daylight envelope for a double-face slope **Right** and **Left** (RS-LS) following the [PERSON] et al. [1] methodology. Images (**a**,**b**) show the daylight envelope construction; image (**c**) is the intersection with the friction cone and (**d**) is the ”restricted daylight envelope” with the lateral limits for planar failure. Figure 7: Stability assessment stereoplot before and after the Barbasquillo cliff’s progressive failure. Image (**a**) shows the actual potential toppling failure for the right and left sides of the cliff: the slope dip angle is 70 degrees. Image (**b**) shows an unstable J2 joint because the pole falls into the yellow envelope: that was the initial situation when the cliff was vertical (90 degrees dip). Figure 6a shows the daylight envelope for a single-face LS (Left Side). In Figure 6b, the expanded daylight envelopes for both left and right faces (LS-RS) are shown, while in Figure 6c, it is proposed that the daylight envelope is restricted by the friction cone. The pole of the bedding plane is inside the restricted daylight envelope, so the plane should be considered unstable, as can be deduced by the slope slide failure. Figure 7a shows the stereoplot assessment of the potential toppling risk in Barbasquillo before the planar sliding.