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Natural Hazards 12: 1-17, 1995. © 1995 Kluwer Academic Publishers. Printed in the Netherlands.

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Soil Liquefaction Potential Induced by the Andalusian Earthquake of 25 December 1884 JOSÉ R. A R A N G O 1, R A F A E L B L A Z Q U E Z 1, JOSÉ C H A C O N 1 and C A R L O S LÓPEZ CASADO 2 1Departamento de Ingenierfa Civil, Universidad de Granada, Spain 2Departamento de Ffsica Téorica y del Cosmos, Universidad de Granada, Spain (Received: 30 December 1993; in final form: 20 July 1994) Abstract. On 25 December 1884, an earthquake of epicentral intensity I0 = IX in the MSK scate caused

great damage 'in a large area in the provinces of Granada and Mälaga, in the south of Spain. The reports of the Spanish, Italian and French Commissions that studied the earthquake described ground phenomena in seven different sites which can be identified as soil liquefaction. By means of dynamic penetration tests carried out in the above sites, the corresponding soil profiles (based on SPT data and water table depth) were established, and the occurrence of liquefäction was proved in five out of seven of these sites. Also, the intensities at such locations and the magnitude of the earthquake were estimated. From the geotechnical data and the cyclic stress ratio induced by the earthquake, liquefaction conditions were confirmed in all the five sites which presumably liquefied. Then, possible values of the minimum ground surface accelerations necessary for the onset of liquefaction at each location were calculated. The results obtained were completed with data reported in six liquefaction case studies from Japan and the United States, from which design charts relating soil acceleration with normalized SPT values for different intensity levels were drawn. Finally, by using standard attenuation curves, the above data were translated into epicentral distances, and good agreement with the known epicentral area was found. As a result, a consistent approach for liquefaction hazard and source location problems has been developed. The proposed method combines in its formulation historical evidence and earthquake engineering techniques. Key words. Seismic liquefaction, epicentral location, ground motion attenuation, isoseismal mapping,

historical earthquakes, microzonation.

1. Introducfion T h e seismic c a t a l o g o f t h e I b e r o - M a g h r e b i a n r e g i o n ( M e z c u a a n d M a r t i n e z S o l a r e s , 1983) c o n t a i n s v e r y v a l u a b l e d o c u m e n t a t i o n a b o u t s e v e r a l d e s t r u c t i v e e a r t h q u a k e s w h i c h o c c u r r e d in S p a i n in o r a f t e r t h e s i x t e e n t h c e n t u r y , with e p i c e n t r a l i n t e n s i t i e s Io g r e a t e r t h a n V I I I in t h e M S K scale; e . g . , C a r m o n a 1504, Io = X; M ä l a g a 1680, I0 = I X ; A r e n a s d e l R e y 1884, I0 = I X ; etc. For the purpose of locating the epicenter of the aforementioned historical earthquakes, isoseismal maps are commonly used. However, the errors involved in this p r o c e s s a r e o f t h e o r d e r o f t e n s o f k i l o m e t e r s , o r e v e n m o r e , especiaUy in cases in w h i c h t h e d e m o g r a p h y o f t h e e p i c e n t r a l r e g i o n s is n o t h o m o g e n e o u s , since t h e n t h e l o c a t i o n o f t h e e p i c e n t e r is s y s t e m a t i c a l l y b i a s e d t o w a r d s t h e m o s t densely populated zones.

JOSÉ R. ARANGO ET AL.

Epicentral locations can be improved by using, in the determination process, not only macroseismic data but geotechnical data as weil, such as soil liquefaction observations. These data, complemented with: (a) in situ testing (undisturbed samples taken from borings, dynamic penetration tests, etc.), (b) empirical relationships between the local intensities, accelerations, and magnitude of the earthquake and the factors governing liquefaction of the ground, and (c) peak acceleration attenuation laws, allow us to draw boundaries for the epicentral area. In order to validate the proposed method, the Andalusian earthquake of 25 December 1884, with an estimated epicentral intensity I0 = IX, has been used. This earthquake, which took nearly one thousand lives and caused great damage in the zone, was extensively studied by three international commissions (López Arroyo et al., 1981; Mufioz and Udias, 1981; López Casado et al., 1992). This information, combined with the additional field testing necessary for reassessing the ground phenomena reported in different sites, have led to the development of a technique for characterizing liquefaction in the field, that could be easily implemented for seismic hazard and microzonation studies.

2. Input Data The magnitude of the Andalusian earthquake used in this report (ML = 6.5-6.7) has been adopted from Mufioz and Udias (1981), who indu¢ed this parameter from the isoseismal map (Fig. 1) assuming an homogeneous propagation of the seismi¢ waves from the fracture zone. The intensities reflected in the map correspond to the MSK s¢ale, but, since in the range of interest (I = VII to I = IX) both the MM and the MSK intensities are similarly assessed, no further distinction between them will be made. The data about focal dept of the earthquake are taken from Mezcua and Martinez Solares (1983) and Mufioz and Udfas (1991). Evidences about soff liquefa¢tion during the period of shaMng correspond to the following sites (López Arroyo et al., 1980): (1) Valle del Rfo Marchän, (2) Cortijo de los Alamos, (3) Santa Cruz del Comercio, (4) Llano de las Donas (near the Cortijo Mudapelo), (5) Pago de las Ventas (Albufiuelas), (6) Rio Bermuza (CaniUas de Aceituno), and (7) S. O. de Vélez Mälaga. All these locations are indicated in the map shown in Figure 2.

3. Field Observations A program of in situ testing of the different soil profiles was devised in order to assess SPT values and the depth of the water table in every site, with the exception of those numbered (5) and (7), which are actually embodied in areas of recent urban growth. The SPT values in the layers, N, were found indirectly, by correlating them with the mean measurements of the dynamic penetration tests performed

SOIL LIQUEFACTION POTENTIAL

3

oL~

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N«it = 10.2, whereas the opposite occurs for I = IX (Nerit = 16.7). In order to estimate the acceleration values at sites (1), (2), (3), (4) and (6), a number of I - a correlation laws has been employed (Fig. 6). In all cases but one (specifically the Medvedev-Sponheuer correlation, 1969), the computed accelerations are greater than those required for the onset of liquefaction, namely, am~nO)=0.22 g, am~~(2)=0.23 g, am~~(3)=0.21 g, amin(4)=0.26 g, and amin(6) = 0. 15 g. Table II summarizes the values of the cyclic stress ratios and minimum accelerations that lead to liquefaction of the soil at the five sites studied. Figures 7 and 8 depict the graphs for evaluating the liquefaction potential expressed in terms of cyclic stress ratio and/or threshold acceleration - for various earthquake intensities and soil penetration resistances. The diagrams are of yes/no type. For instance, a point on the left of the boundary defined by intensity VII means that the sand belongs to a layer likely to liquefy for intensities equal or greater than VII at the site. Similarly, a point located in between the I = VII and I = VIII curves shall liquefy for intensities equal or greater than VIII, and so will happen to a point on the right of the IX intensity curve for I > IX at the site. The equations of the boundary curves shown in Figure 7 are: VII ~< I ~< VIII ~ zig' = 10 -1» exp (4.32 N1) VIII ~< I ~< IX--~ ~-/o" = 0.041 exp (0.105 N1)

(7-1) (7-2)

Similarly, in Figure 8 we have: VII 0

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16

JOSÉ R. ARANGO ET AL.

Acknowledgement The work reported herein is part of the research project No. AMB92-0656, funded by the Comisión Interministerial de Ciencia y Tecnologfa of Spain (C.1.C.Y.T). The financial support received from this Institution is gratefully recognized. References Arango, J. R.: 1993, Anälisis de terremotos históricos por sus efectos: Licuefaceión de suelos y dafios en los edificios, E1 terremoto de Andalucfa, PhD Dissertation, Departamento de Ingenieria Civil, Universidad de Granada, Spain (in Spanish). Boore, D. M., Joyner, A., Oliver, A. A. and Page, R. A.: 1980, Peak acceleration, velocity, and displaeement from strong-motion records, BuU. Seis. Soc. Am. 70, 305-321. Campbell, K. W.:1981, Near-source attenuation of peak horizontal acceleration, BuU. Seis. Soc. Am. 71, 2039-2070. Chiaruttini, C. and Siro, L.: 1981, The correlation of peak ground historical acceleration with magnitude, distance and seismic intensity for Friuli and Ancona, Italy, and the Alpine Belt, Bull. Seis. Soc. Am. 71, 1993-2009. Comisario Regio:1888, Memoria, M. Minuesa de los Räos, impresor, Madrid (in Spardsh). Comisión de la Academia de Ciencias de Paris: 1890-1893, Estudios referentes al terremoto de Andaluefa, Boletin de la Comisión del Mapa Geológico, Imprenta y fundición Tello, Madrid (in Spanish). Fernändez de Castro, M., Lasala, J. P., Cortäzar, D. and Gonzalo y Tarin, J.: 1885, Terremoto de Andalucta, Informe de la Comisión Espafiola nombrada para su estudio dando cuenta del estado de los trabajos en 7 de marzo de 1885, Imprenta de M. Tello, Madrid (in Spanish). López Arroyo, A., Martin, A. J. and Mezcua, J.: 1981, Terremoto de Andalucfa: Influencia en sus efectos de las condiciones del terreno y del tipo de construcción, en E1 terremoto de Andalucia del 25 de diciembre de 1884, Instituto Geógrafico Nacional, Madrid, pp. 5-94 (in Spanish). López Casado, C., Delgado, J., Pélaez, J. A., Peinado, M. A. and Chacón, J.: 1992, Site effeets during Andalusian earthquake (12/25/1884), Proc. Tenth World Conf. on Earthq. Engin., Balkema, Rotterdam, Vol. 2, pp. 1085-1089. Martin Martin, A. J.: 1984, Riesgo sismico en la Pentnsula Ibérica, PhD thesis, Univ. Politécnica de Madrid, Publ. del Instituto Geogräfico Nacional, 234 pp. (in Spanish). Medvedev, A. V. and Sponheuer, W.:1969, Scale of seismic intensity, Proc. IV World Conf. Earthq. Engin., Santiago, Chile. Mezcua, J. and Martinez Solares, J. M.: 1983, Sismicidad del ärea ibero-mogrebi, Publ. 203, Instituto Geogräfico Nacional, Madrid, pp. 1085-1089 (in Spanish). Mufioz, D. and Udias, A.: 1981, Estudio de los parämetros y series de réplicas del terremoto de Andalucfa del 25 de diciembre de 1884 y de Ia sismicidad de la región Granada-Mälaga, en: El terremoto de Andalucla de 1884, Instituto Geogräfico Nacional, Madrid, pp. 95-139 (in Spanish). Mufioz, D. and Udias, A.: 1991, Three large historical earthquakes in southern Spain, in: Seismicity, Seismotectonics and Seismicity, and Seismic Risk of the Ibero-Maghrebian Region, Monograph 8, Instituto Geogräfico Nacional, Madrid, pp. 175-182. Murphy, J. R. and O'Brien, L. J.: 1977, The correlation of peak ground acceleration amplitude with seismic intensity and other physical parameters, Bull. Seis. Soc. Am. 67,877-915. Seed, H. B. and Idriss, I. M.: 1971, Simplified procedure for evaluating soil liquefaction potential, J. Soil. Mech. and Found. Div., A S C E SM9, 1249-1273. Seed, H. B. and Idriss, I. M.: 1982, Ground Motions and Soll Liquefaction During Earthquakes, Monograph, Earthquake Engineering Research Institute, California. Seed, H. B., Tokimatsu, K., Harder, L. F. and Chung, R. M.: 1984, The influence of SPT procedures in soil liquefaction resistance evaluations, Report UCB/EERC-84/15, Earthquake Engineering Research Center, University of California, Berkeley. State Capital Construction Commission: 1974, Earthquake Resistant Design Code for Industrial and Civil Building TJll-74, China Publishing House, Peking, China.

SOlL LIQUEFACTION POTENTIAL

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Taramelli, T. Mercalli, G.: 1886, I terremoti Andaluci cominciati il 25 dicembre 1884, Atti Acad. Lincei 283, 116-222 (in Italian). Vanelli, F. and Benassi, E.: 1983, Penetrómetro Dinämico Sunda DL030, Studio de Geologia e Meccanica dei Terreni, Bologna, Italia. Zhou. S. G.: 1981, Influence of fines on evaluating liquefaction of sand by SPT, Proc. Int. Conf. on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics, St. Louis, Missouri, Vol. II, pp. 167-172.