O R I G I N A L P A P E R
Combined effects of blasting and geological structure on rock mass stability—a case study from the Marrakech–Agadir highway, Morocco
Taoufik Benchelha1• Toufik Remmal1•Rachid El Hamdouni2 •Hussein Ejjaouani3• Hammou Mansouri3• Fouad El Kamel1•Kawtar Lakroud1
Received: 1 October 2015 / Accepted: 2 March 2016 Springer-Verlag Berlin Heidelberg 2016
Abstract The Marrakech–Agadir highway crosses mountainous areas of the Western High Atlas of Morocco with a high risk of slope instability. The use of explosives as an excavation method, especially at kilometric point 33 on the Imintanout–Argana section, has triggered major ruptures. The regional geological setting, together with the lithological and structural characteristics of the rock mass, represent the major factors influencing this operation where the degree of disturbance is estimated as 0.82. The studied slope is located along the trajectory of a submeridian fault corridor remobilised because of blasting during excavation works. This slope reveals instabilities associated with tec- tonic planes (F1 and F2) and/or bedding (S0) and the
presence of argillites and siltstones that coincide with bedding. These unconsolidated layers, inclined in the direction of excavation, act as slide planes. Structurally, the Pk33 slope can be subdivided into three zones depending on the displacement type being recorded and may be a fortiori related to the geomechanical properties of the substrate. The rheological characteristics of zones B and C, highly fractured and with low competence, respectively, explain their relatively different displacement patterns from that of zone A. The maximum instantaneous explo- sive load used for offloading the upper part of the sliding mass has been estimated in order to increase the safety factor for the instable slope.
Keywords Slope instabilityBlasting Rock mass damageStructural controlHigh AtlasMorocco
Introduction
The geological environment and the mechanical properties of rock slopes are deciding factors in the stability of the environment after excavation. There are many external disturbances that can trigger landslides (Tatard2010): (1) an increase in the slope angle, (2) an increase in the load on the slope, (3) shallowing of the water table and the asso- ciated pressure, (4) the slope under earthquake loading.
In excavation works, mining, and quarrying operations, both stratigraphic and fissural discontinuity surfaces con- trol the propagation of fractures into rocks during blasting (Nateghi2011; Gaillard and Panigoni2012; Go¨rgu¨lu¨ et al.
2013). The microstructure of blast rocks and their natural imperfections influence and complicate the dynamic frac- ture procedure by both creating multiple fractures and bifurcating individual fractures (Scott 1999). A controlled
& Rachid El Hamdouni
[email protected] Taoufik Benchelha [email protected] Toufik Remmal [email protected] Hussein Ejjaouani [email protected] Hammou Mansouri [email protected] Fouad El Kamel [email protected] Kawtar Lakroud [email protected]
1 GAIA Laboratory, Aı¨n Chock Sciences Faculty, Hassan II University, Casablanca, Morocco
2 Civil Engineering Department, ETSICCP, Granada University, Campus Fuentenueva, s/n, 18071 Granada, Spain
3 Laboratoire Public d’Essai et d’Etudes (LPEE), Casablanca, Morocco
DOI 10.1007/s10064-016-0867-5
blasting function of different quality of rock mass must be used to avoid instability (Singh et al.2014). Utilising sta- bility charts to estimate the stability of cutrock slopes without considering the rock mass disturbance may lead to significant overestimations (Li et al.2011).
The multiplicity of geomechanical properties is always predetermined by the geological structure of the massif under consideration (Cojean 2003). Detailed knowledge of the fracture system affecting a rock mass is essential for ana- lysing the conditions that allow deformation and rupturing to occur. Attention must be paid to directional families of dis- continuities, their classification and degree of connectivity, and their geometric and geotechnical parameters.
The example chosen in this case, to study the impact of blasting on slope stability, is a rock slope located between kilometric points 32?460 and 34?560, on the Imi- ntanout–Argana section of the Marrakech–Agadir highway (Fig.1). The lithological and structural aspects of the slope have been identified by considering the regional geological setting to explain the rock mass breakout conditions.
The degree of disturbance generated by blasting is evaluated using the Hoek–Brown failure criterion (Hoek et al.2002), which is based on the strength parametersrci, GSI and mi. These latter take into consideration the effective mechanical properties of the rock.
Regional geological setting
The Imintanout–Argana highway section is located in the Argana Triassic Basin (Fig. 1). Lithologically, this com- prises a thick, monotonous, wine to red-coloured detrital series that includes, from bottom to top, conglomerates, red sandstones, alternations of mudstones, argillites, and locally saliferous marls. At the top of the succession, doleritic basalt flows indicate the beginning of the Atlantic Ocean extension (Duffaud et al. 1966).
The current structure of the formations was acquired during the NNW–SSE to NW-trending Triassic distension, superimposed by tertiary deformations related to N–S trending compression (Medina1994). These correspond to two tectonic episodes: the first generated a system of conjugate faults—ENE–WSW (sinistral reverse faults) and N–S to NNE–SSW (dextral faults) associated with folding oriented NW–SE to WNW–ESE; the second corresponds to a reactivation of these same structural features as reverse faults. The NNE–SSW faults show a sinistral strike-strip motion. Due to the absence of detrital deposits, the thinning of the series to the west, and dominant tectonic style (eastward dipping faults and westward dipping strata), the overall structure of the corridor appears as a half-graben oriented to the west.
Fig. 1 Geological setting and situation of the slope Pk33 on the Imintanout–Argana section of Marrakech–Agadir highway
In the region of Amzri, the location of the excavated area (Fig.2), the structure is dominated by NNE–SSW- trending and ESE-dipping faults, which cut through the sandstone layers. These latter form tilted blocks to the west, 0.5–2 km wide and approximately 10 km long. The overlying clays are partly affected by this fault network, and appear folded due to their ductile properties.
A fault plane analysis shows a NW–SE elongation direction, as well as NE–SW, orthogonal to the first, related to N100 trending faults, and which, according to the fault plane mapping, is clearly posterior to the NNE–SSW trending faults (Fig.2).
Instability study of the excavation slope Geological aspect
The unstable slope comprises two sliding blocks separated by submeridian faults that extend to the opposite slope, over a fault corridor about 30 m wide (Fig.3).
At the top of the slope, the sliding is well-delimited. It extends over a global kilometre-scale line, in the form of a 2–5-m wide strip, with a collapse of up to 0.5 m. Further down in the sandstone massif, there is no clear and
continuous fracture line like that observed at the crest.
Deformation is more diffuse, dissipating through local fractures, loose densely fractured rock, or reactivation of deformation along the clayey stratigraphic joints.
On the slope scale, the bedrock comprises alternating layers of sandstones, argillites, and reddish siltstones (Fig.4). The sandstone beds, particularly thick, from 2 to 3 m, are intensely fractured with individualisation of blocks, and rock masses that are detached from their immediate bedrock by open and locally cracked fissures.
The clayey-silty formations generally do not exceed a metre in thickness and, in some levels, present a marly composition. Drilling shows that towards the bank down- slope, clay formations dominate at the expense of the sandstones, particularly in the south where they are the main lithological component.
Structurally, the rock massif is characterised by three main sets of discontinuities which generate local instabil- ities (Figs. 4b, 5): S0: this corresponds to the bedding, dipping to the northwest with tilting of between 20 and 30. The characteristic plane is 350/25; F1: these are sub- vertical discontinuities dipping slightly to the northwest, with a maximum plane of 320/85; F2: these are subvertical discontinuities dipping to the southwest, with an average maximum plane of 250/75.
Fig. 2 Structural map of the region of Amzri where slope Pk33 is located, withaa stereographic projection of the structural elements andba schematic cross section through the Triassic formations (view location on Fig.1)
The combination of these three families generates instabilities with variable amplitudes. In this case, there are three types of potential ruptures: planar, toppling, and wedge (Fig.6). The F1 family is considered extre- mely unfavourable for planar ruptures, while the inter- section of families F1 and F2 generates lines, which is considered unfavourable for wedges. This is the same for the wedge I2, produced by the intersection of families S0 and F2. An analysis of the ruptures by toppling shows that no family of discontinuities is easily subject to rupturing. It should also be emphasised that families F1 and S0are close to planar rupture conditions, since their planes are near the area of theoretical instability. How- ever, other ruptures through secondary planes cannot be ruled out.
The variability in the directions of these plans and slope irregularities promote these ruptures, which can be seen clearly in the field (Fig.7).
Geotechnical aspects
A geotechnical survey (seven boreholes, two exploratory galleries) and laboratory tests (uniaxial compressive strength, shear stress, p wave sound speed) were carried out to determine the geotechnical characteristics of the exca- vation. The results recorded are reported in Table1. All
structural data, borehole conditions (boreholes situation), and the locations of the different instrumentations are shown in Fig. 8.
The amount of soil being excavated from the slope during earthworks is on the order of 2.5 million m3, with an elevation of 120 m. The volume of sliding rock mobilised after blasting is estimated as 1.2 million m3 based on geological surveys and geological sections cross-cutting different boreholes.
Methods and equipment used
Instruments used for the slope movement auscultation (Fig.8) included targets, inclinometers, levelling, pegs, crack meters, and geophones. These different instruments are used, respectively, to establish the movement of various points within the slope, deduce sliding surfaces, identify vertical movement, measure movement along large par- ticularly upper fissures, determine the movement direction and magnitude of the destabilised mass, and to measure seismic wave propagation.
Results obtained
The results obtained during the first slope excavation, having used an instantaneous load of 50 kg, allow three Fig. 3 Location of slope Pk33
across the trajectory of a fault corridor;a,btension cracks observed on different parts of the slope;Ffault corridor at the opposite side the sliding area.
Note the rupture of the sandstone formations in contact with the fault; : principal scarps of landslides; : fracture; : direction of displacement
Fig. 4 Geology of the excavation area (a) showing the locations of the structural elements (b). Bedding plane;
fault; crown of the slide and, fault
Fig. 5 a Detailed view of a section through the sandy-pelitic formation of the excavation, showing the disposition of the principal discontinuity families.S0bedding plane;F1andF2fracture planes.
bDiagram of discontinuity isodensity related to bedding planes (S0) and fracture planesF1andF2
sliding areas to be distinguished, with a general displace- ment of 60from the axis of the highway.
• Zone A is essentially marked by the appearance of fissures at the top, resulting from displacement that is well-recorded by inclinometers 2, located halfway up the slope, and which shows a moving strip of between 30 and 45 m. Inclinometer 5, with a 20-m depth located below the limit of the landslide shows no significant displacement. Down the slope, incli- nometer 3 shows that the moving band is 7 m wide (Fig.9).
• Zone B located on the path of a fault corridor apparently inherited from Triassic distension, is affected by strong cracking. Deformation values from levelling indicate that the points which experience the greatest subsidence compared to the reference point are located between Pk33 ?200 and Pk33?300 on berm 2, between Pk33?300 and Pk33?350 on berm 7, and between Pk33?350 and Pk33?400 on berm 8 (Fig.9).The junction of these various, relatively super- ficial, subsidences (2–4 mm) describes a band of hectometric width, oriented in the direction of the fracturing (Fig.9). The crack meter located on this fracture indicates a bedding plane movement of approximately 8 cm, recorded over a 30-day interval during the shooting period.
• Zone C is lithologically distinguished from zone A by the dominance of clay. It ranges from a few decimeters to several meters in thickness. Sliding is associated with an important rock fall of large boulders (up to 2 m in diameter). Mobilisation of these boulders is facilitated by the soft bedding planes formed by the argillites and siltstones. Inclinometer 4, located beyond the tensile fractures, recorded no significant movement (Fig.9).
Satellite images taken at different times between 2011 and 2014 (Fig.10) reflect a stepped slope movement con- sistent with that obtained by levelling measurements taken on different berms. This movement is accommodated by the NNW–SSE-trending submeridian fractures and NE–
SW fractures. The displacement highlighted by the crack- ing in the upper berm, which is considered a benchmark level, is about 4 m (Fig.10). It should be noted, however, that from 2013 to 2015, the movement has remained stable, possibly due to the offloading of the sliding surface.
Structural model of the slope: contribution of exploratory drifts
Two hectometric exploratory drifts, G1 and G2, have been excavated in clay-sandstone formations with a submeridian orientation (Fig.8). The drifts crosscut massive sandstone beds intercalated by clayey-silty and locally conglomeratic layers. The sandstones are dislocated in metric blocks with no matrix. The argillites are usually moistened by water seepage. Discontinuities observed in these drifts are sub- vertical, slightly inclined in the direction of the slide, with varying thicknesses of up to 50 cm in diameter, especially in the indurated sandstone levels. Structurally, they are constrained by a tension rupture that is generally expressed by fissures opening as pull apart or en echelon tension gashes.
These different structures deviate approximately 45 from the slope of the major slide plane, as measured by the inclinometers (Fig.11a). Structurally, the geometry of the structures deduced from this organisation is homothetic with theoretical fracturing models related, in this case, to normal dextral strike-slip faults (Fig.11b). Moreover, these different fractures are emplaced around a 57/15W axis close to the bedding plane (Fig.11c). Sliding in the Fig. 6 Rupture analysis of the unstable slope, Pk33, on the Imintanout–Argana section of the Marrakech–Agadir Highway.aPlanar ruptures, bwedge ruptures,ctoppling ruptures (projection, on a Schmidt’s lower hemisphere net)
clay formations seems to be an important slope instability factor.
Impact of explosives on slope stability Analysis of disturbance factors
During the first ground excavation from the slope at Pk33, the use of explosives contributed to altering the rock
slope’s original resistance characteristics and led to the displacement of a large rock mass (Fig.9).
Determining the blast disturbance factor D
Hoek et al. (2002) define factor D as an evaluation of the degree of disturbance experienced by the rock mass, as a result of blast damage. This factor varies between 0 for intact rock masses and 1 for highly damaged ones.
Fig. 7 Instabilities predetermined by the geological structure of the slope.a,bDetailed observations of fracturing in the upper berms of the slope. Combination between bedding planes presenting an incline in the direction of the slope plan, and joint planes, results in the individualisation of unstable boulders.cTearing structures are seen in some berms lower on the slope (arrows). The ruptures are
predetermined by the geological structure of the rock mass. We can also note accumulations of blocks that have fallen from the highly fractured slope.dTensile fractures observed on a berm, indicative of an imminent collapse of the rock mass. The direction of these fractures conforms with directional families F1and F2
The input data for the Slide software (Rocscience2005), which was utilised in this case, comes from in situ inves- tigation (density,rci,c0,/0; Table1), supplemented by the geological strength index (GSI) and mi values (Hoek and Brown1997; Hoek2007; Wyllie and Mah2004; Marinos et al. 2005). Figure12a summarises the landslide mod- elling parameters.
The sensitivity curve (Fig.12b) shows that the safety factor decreases from 1.32 to 0.9 when the disturbance factor varies from 0 to 1. The slope becomes unsta- ble (SFB1) onceDC0.82. This value thus corresponds to the degree of perturbation with a limit equilibrium for slope stability. It falls squarely between the two values calculated by Hoek–Brown methodology (Hoek et al.
2002) for slopes excavated by blasting. Indeed, the value of Dvaries between 0.7 for controlled blasting and 1 in other situations.
Influence of disturbance factor D on parameters ceq0and /eq0
The calculation of the equivalent Mohr–Coulombceq0 and /eq0parameters is provided by the Hoek–Brown equations (Hoek et al.2002):
/0eq¼sin1 6ambsþmbr03na1
2 1ð þaÞð2þaÞ þ6ambsþmbr03na1
" #
ð1Þ Table 1 Geotechnical characteristics of materials from Pk33
Drilling RQD (%) Depth (m) Nature of the material Density (c; KN/m3) rci(MPa) Rocky mass Joints
u0() c0(KPa) u0() c0(KPa)
4110 57 13.5 Sandstone 80.4 51 400
40 Argillites 92 23 140
4111 38 10 Sandstone 23.3 72.2 55 146
38 Sandstone–siltstones–argillites 22.3 76 26 64
55 Argillites–sandstone 23.6 53 29 251
4113 46 34 Sandstone 23.1 85 47 274
4115 34 25 Sandstone–argillites–siltstones 25.3 64 32 52 25 2
30 Sandstone–argillite siltstones 32 161 18 50
4116 45 16 Sandstone–argillites 24 28.6 31.5 32.5
25 Argillites 23.5 25.5 28 126.1
4117 40 16 Argillites 24.1 15.3 28 126
4118 56 17 Argillites 24.5 27 28 160.5
Fig. 8 Locations of the geotechnical measuring instruments
c0eq¼
rcið1þ2aÞsþð1aÞmbr03n
sþmbr03n
a1
1þa ð Þð2þaÞ
ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 1þ6ambsþmbr03na1 r
1þa ð Þð2þaÞ
ð Þ
ð2Þ
where: mb¼miexpGSI1002814D
; s¼expGSI10093D
; a¼12þ16 eGSI=15e20=3
; r3n¼r03max=rci:
GSI is the geological strength index andDrepresents the rock mass disturbance (blast damage) factor.
Fig. 9 Directions and values of the displacements recorded by the inclinometers. Note the presence of transverse or inclined fissures compared to the general sliding. The fissuring is evidenced by the levelling alignment recorded on the slope
r03max, in the case of slope stability, is expressed by:
r03max
r0cm ¼0:72 rcH0cm 0:91
where:His the height of the slope;cis the density of materials; andr0cmrepresents the compressive strength of the rock mass. It is given, in the case wherer1\r03\rci/ 4, by the following equations:
r0cm¼rci:ðmbþ4sa mð b8sÞÞ ðmb=4þsÞa1 2 1ð þaÞð2þaÞ
The effective parameters ceq0 and /eq0 are thus repre- sented according to the GSI (between 10 and 100) and by two values ofD: 0 in the absence of any disturbance, and 0.82 in limit equilibrium conditions.
The respectiveceq0and/eq0correction coefficients fceq0 (fceq0=ceq0D = 0.82/ceq0D = 0) and f/eq0 (f/eq0 =/eq- D= 0.82//eq0
D= 0; Fig.13) increase with the GSI. For a GSI
of 40 representing the slope Pk33, these coefficients cor- respond to fceq0=0.49 and f/eq0 =0.67.
Stabilisation of the slope by offloading: determining the maximum instantaneous explosive load
To stabilise the moving rock mass, a result of the first ground excavation, offloading works were performed using explosives. This operation first requires knowledge of the blast-induced acceleration and ground vibrations in order to calculate the maximum instantaneous explosive load to use in shooting. To this end, and based on the sliding slope simulated model (Fig. 11), the sensitivity curve giving the SF according to the horizontal ground vibration (Fig.14) shows that the SF decreases from 1.32 to 0.8 when the horizontal ground vibration varies from 0 to 0.2 g. The slope becomes unstable (SFB1) onceahC0.11 g.
Fig. 10 Satellite images taken at different times showing slope Pk33 situated on the Imintanout–Argana section of the Marrakech–Agadir highway. The upper berm indicated by thearrowallows the slope displacement to be identified
Furthermore, the expression proposed by Dowding (1985) shows the ground vibration produced during blast- ing depending on the maximum instantaneous explosive charge used and the distance between blast and receptor.
a¼314 386
30:5 D 1:84
V 3050 1:45
Q 4:5 0:28
2:446 c 0:28
ð3Þ
a: ground vibration produced by the blast (g); D: dis- tance (m) between blast and receptor; v: speed of the p wave in the volume (m/s) taken as 2500 m/s corresponding to the usual value for sandstone; Q: active load (kg); c:
volume density (t/m3) taken as 2.5 t/m3.
Figure15 shows the acceleration for various instanta- neous charges (between 1 and 28 kg) and for three dis- tances between the blasting point and the sliding mass (80, Fig. 11 aStructural model of the slide on slope Pk33 inferred from
geological data (exploratory drifts and drilling) and geotechnical measurements (inclinometers).bTectonic model.C,R1,R0,Tfaults
(Riedel shear model). c Isodensity diagram of discontinuities measured in excavation drifts G1 and G2.PCyclographic alignment of fracture poles,S0bedding; andathe pole to the plane P (c)
Fig. 12 aSliding model for slope Pk33.bSensitivity curve showing the safety factor (SF) according to the disturbance factor (D)
90, and 100 m). Thus, the maximum instantaneous loads, 6, 11, and 21 kg, respectively, correspond to the distances 80, 90, and 100 m.
In the interest of safety, the instantaneous load applied during offloading works is 5 kg.
When using explosives for offloading works the vibra- tions propagated must be characterized in order to preserve the surrounding structures (Gonza´lez-Nicieza et al. 2014;
Hajihassani et al.2015)
Seismic wave recordings of the blasting measured at three geophones, G1, G2, and G3, located, respectively, 25, 85, and 125 m from the shooting point (Fig.8), drop sharply from a frequency of 4–8 Hz at G1, to 0–5 Hz at G2, and 0–1 Hz at G3 (Fig.16). This decrease in maximal frequency shows that the field contains very open discon- tinuities that block the passage of higher frequencies (Gaillard and Panigoni 2012). The existence of faults detected both on the surface and underground drifts between the source and the different geophones supports this relationship. In parallel, the maximum displacement decreases from a magnitude of 0.012 mm (G1) to 0.007 (G2) before returning to 0.01 mm (G3; Fig.16). This
increase in magnitude, despite the distance from the source, is explained by the proximity of the transverse crack.
Conclusions
The particularity of slope Pk33, realised on the mountain side, is that it is primarily located along the trajectory of a submeridian fault corridor remobilised as a consequence of blasting during excavation works. This slope reveals instabilities associated with tectonic planes (F1and F2) and/
or bedding (S0), and ruptures by wedging caused by the intersection of the F1and F2planes. Boulder mobilisation is encouraged by the presence of argillites and siltstones that coincide with bedding. These unconsolidated layers, inclined in the direction of excavation, act as slide planes.
Structurally, the Pk33 slope can be subdivided into three zones depending on the displacement type being recorded.
These zones may be a fortiori related to the geomechanical properties of the substrate. Zone A, which is dominated by indurated sandstone formations with clay intercalations, shows the maximum instability with displacement of more Fig. 13 The correction coefficients ofceq0and/eq0 according to the GSI
Fig. 14 Sensitivity curve showing the safety factor (SF) according to the horizontal ground vibrationah
Fig. 15 Ground vibration produced by the blasting depending on the active charge
Fig. 16 The Fourier transformation and displacements recorded by the three sensors during the same blasting on slope Pk33 with an instantaneous load of 5 kg
than one million m3of rock towards the highway. Simu- lations performed in similar contexts show that the equiv- alent Mohr–Coulombceq0and/eq0parameters are reduced by 51 and 33 %, respectively, and the slope safety factor decreases by about 20 %. Zone B is located above an inherited fault corridor, which crosscuts bedrock richer in clay. Zone C, dominated by clay, is the first to respond to blasting through the initialisation of a displacement along an apparent slide surface.
The presence of poorly filled discontinuities or those with low strength infill can also cause explosive gas emissions that disturb the movement of shot rock (Delille 2012). The rheological characteristics of zones B and C, highly fractured and with low competence, respectively, explain their relatively different displacement patterns from that of zone A. However, in some cases, water released by sandstone beds via fractures is collected by the clay joints which, once ductile, reduce soil resistance.
In the case of vibration propagation, bedrock structure and fracturing is somewhat more important than the pet- rographic nature of the rock. Faults act as barriers and reduce the vibration waves.
Finally, it is proposed that the maximum instantaneous explosive charge be calculated using the Dowding (1985) formula before any excavation takes place, in this case, by offloading in order to reduce the influence on slope stability.
Acknowledgments This research was performed in a program of col- laboration between Granada University in Spain and Hassan II University in Morocco. This collaboration was supported by a grant for exchange and cooperation between Europe and the Maghreb in the Erasmus Mundus–Al Idrisi project. This work has also been possible thanks to the Moroccan Public Laboratory of Testing and Studies (LPEE).
References
Cojean R (2003) Les processus de de´formation et rupture des versants instables. Roˆle des structures ge´ologiques, des mate´riaux et des conditions hydrauliques. Apports et limites de la mode´lisation dans l’analyse de sce´narios d’e´ve´nements. Dissertation (Habil- itation a` diriger des recherches), University of Marne la Valle´e (France)
Delille F (2012) Recherche d’une pre´diction de fragmentation charge par charge pour les tirs a` ciel ouvert. Dissertation (PhD thesis), Ecole Nationale Supe´rieure des Mines de Paris
Dowding CH (1985) Blast vibration, monitoring and control. Prentice Hall, Englewood Cliffs
Duffaud F, Brun L, Plauchut B (1966) Le bassin du Sud-Ouest marocain. In: Reyere D (ed) Bassins sedimentaires du littoral
africain. Publication de L’Association Services Ge´ologiques Africains, Paris, pp 5–26
Gaillard C, Panigoni T (2012) Influence du terrain dans la propagation des vibrations. Ge´otechnique Francophone. JNGG’2012, Jour- ne´es Nationales de Ge´otechnique et de Ge´ologie de l’Inge´nieur, Bordeaux, 4 au 6 juillet 2012, p 8.http://www.geotech-fr.org/
sites/default/files/congres/jngg/JNGG-2012-99.pdf. Accessed 27 July 2015
Gonza´lez-Nicieza C, A´ lvarez-Fernandez MI, Alvarez-Vigil AE, Arias-Prieto D, Lo´pez-Gayarre F, Ramos-Lopez FL (2014) Influence of depth and geological structure on the transmission of blast vibrations. Bull Eng Geol Environ 73:1211–1223.
doi:10.1007/s10064-014-0595-7
Go¨rgu¨lu¨ K, Arpaz E, Demirci A, Kocaslan A, Dilmac MK, Yu¨ksek AG (2013) Investigation of blast-induced ground vibrations in the Tu¨lu¨ boron open pit mine. Bull Eng Geol Environ 72:555–564. doi:10.1007/s10064-013-0521-4
Hajihassani M, Armaghani DJ, Marto A, Mohamad ET (2015) Ground vibration prediction in quarry blasting through an artificial neural network optimized by imperialist competitive algorithm. Bull Eng Geol Environ 74:873–886. doi:10.1007/
s10064-014-0657-x
Hoek E (2007) Practical rock engineering. Hoek’s corner in Rocscience web. https://www.rocscience.com/learning/hoek-s- corner/books. Accessed 27 July 2015
Hoek E, Brown ET (1997) Practical estimates of rock mass strength.
Int J Rock Mech Min Sci 34:1165–1186. doi:10.1016/S1365- 1609(97)80069-X
Hoek E, Carranza-Torres C, Corkum B (2002) Hoek–Brown failure criterion-2002 edition. Proc NARMS-Tac Conf Tor 1:267–273 Li AJ, Merifield RS, Lyamin AV (2011) Effect of rock mass
disturbance on the stability of rock slopes using the Hoek–Brown failure criterion. Comput Geotech 38:546–558
Marinos V, Marinos P, Hoek E (2005) The geological strength index:
applications and limitations. Bull Eng Geol Environ 64:55–65.
doi:10.1007/s10064-004-0270-5
Medina F (1994) Evolution structurale du Haut Atlas occidental et des re´gions voisines, dans le cadre de l’ouverture de l’Atlantique Central et de la collision Afrique-Europe.
Dissertation (PhD thesis) Mohamed V University, Rabat, Morocco
Nateghi R (2011) Prediction of ground vibration level induced by blasting at different rock units. Int J Rock Mech Min Sci 48:899–908
Rocscience (2005) 2D limit equilibrium analysis software slide 5.0.
http://www.rocscience.com. Accessed Mar 2014
Scott A (1999) Effective blast engineering. In: Explo’99, AusIMM, pp 57–63.http://www.ausimm.com.au/publications/epublication.
aspx?ID=2938. Accessed Mar 2014
Singh PK, Roy MP, PaswanRanjit K (2014) Controlled blasting for long term stability of pit-walls. Int J Rock Mech Min Sci 70:388–399. doi:10.1016/j.ijrmms.2014.05.006
Tatard L (2010) statistical analysis of triggered landslides: implica- tion for earthquake and weather controls. Dissertation (PhD thesis), Joseph-Fourier University. Grenoble I, France
Wyllie DC, Mah C (2004) Rock slope engineering. CRC Press, Taylor and Francis Group, New York
