*Natural Hazards - Impacts, Adjustments and Resilience*

relatively very short period of time shows that the heavy damage caused during the succesive seismic events occurred in this country with intensities ≤VII (**Table 2**), have highlighted the inadequacy of each previous earthquake-resistant standard. All of them have been imposing more rigorous technical requirements and guidelines for the construction of new buildings and major rehabilitation works but have not prevented structures built under the previous rules from being exposed to the risk of collapse or seismic damaging. In addition, the rule currently in effect also do not guarantee the absence of damage to new buildings raised after the effective date of the law and only aims to avoid the immediate collapse of the structures.


**319**

**Table 2.**

*Source: Instituto Geográfico Nacional (IGN).*

*Effects of Earthquakes on Buildings in the Ibero-Maghrebian Region*

**Date Time Lat. Long. Depth** 

**(km)**

1963/01/19 20:50:29 382.167 −10.500 — VI 3.3 MbLg Abanilla 1964/01/29 01:47:53 370.583 −36.233 5 VI 3.7 MbLg Dílar 1964/03/15 22:30:26 361.317 −77.500 30 VII 6.2 MbLg Golfo de

1964/06/09 02:33:35 377.367 −25.667 5 VII 4.8 MbLg Galera 1964/09/09 09:39:45 370.850 −36.200 5 VII 4.3 MbLg Otura 1967/08/03 00:34:13 383.567 −12.883 5 VI 3.9 MbLg Jumilla 1969/02/28 02:40:32 359.850 −108.133 20 VIII 7.8 Mw SW Cape St.

1970/03/14 15:48:09 424.800 16.800 — VI 4.3 MbLg Ílles de

1972/03/16 21:31:32 374.200 −22.450 5 VII 4.8 MbLg Partaloa 1976/09/26 04:29:20 388.867 −0.5933 5 VI 4.0 MbLg Aielo de

1977/06/06 10:49:12 376.450 −17.283 9 VI 4.2 MbLg Lorca 1979/01/16 00:55:16 428.883 −71.517 80 VI 3.6 MbLg Becerreá 1979/03/20 21:53:56 371.633 −38.017 5 VI 4.1 MbLg Chimeneas 1979/06/19 03:55:53 371.483 −35.967 5 VI 3.2 MbLg Cájar 1979/06/20 00:09:06 372.483 −34.917 60 VI 4.5 MbLg Beas de

1979/07/30 00:55:25 371.133 −36.733 5 VI 3.7 MbLg Alhendín 1979/07/31 21:43:20 371.167 −36.033 5 VI 3.9 MbLg Gójar 1979/11/25 01:56:27 368.650 −37.733 5 VI 3.4 MbLg Lentegí 1979/12/18 05:47:34 428.883 −71.633 20 VI 4.2 MbLg Becerreá 1980/11/11 10:59:46 378.333 −52.150 5 VI 4.1 MbLg Hornachuelos 1988/08/20 13:03:03 372.067 −37.667 2 V-VI 3.9 MbLg Chauchina 1989/12/20 04:15:05 372.250 −73.917 23 VI 5.0 MbLg Ayamonte 1991/08/14 10:32:08 387.550 −0.9600 2 VI 4.1 MbLg Caudete 1993/12/23 14:22:35 367.800 −29.367 8 VI-VII 5.0 MbLg Berja 1995/11/26 05:39:40 380.383 −12.700 2 V-VI 4.1 MbLg Alguazas 1995/11/29 23:56:28 428.167 −73.033 9 VI 4.6 MbLg Triacastela 1995/12/24 14:29:21 428.600 −73.150 15 VI 4.6 MbLg Baralla 1997/05/21 23:50:45 427.833 −72.583 13 VI 5.1 MbLg Triacastela 1999/02/02 13:45:17 380.963 −15.014 1 VI 4.7 MbLg Mula 2005/01/29 07:41:32 378.535 −17.555 11 VII 4.8 Mw Aledo 2011/05/11 15:05:13 377.196 −17.076 2 VI 4.5 Mw Lorca 2011/05/11 16:47:26 377.175 −17.114 4 VII 5.1 Mw Lorca 2016/01/25 04:22:01 356.004 −38.056 12 VI 6.3 Mw Alborán Sur

*Earthquakes felt with intensities VI to VII in Spain between January 1, 1950 and December 31, 2019. Note that earthquakes of magnitude M < 5 can also cause effects of intensity VII in direct relation to the shallowness.* 

**Int. Mag. Epicenter**

Cádiz

Vincent

Cerdanya

Malferit

Granada

*DOI: http://dx.doi.org/10.5772/intechopen.94739*


*Effects of Earthquakes on Buildings in the Ibero-Maghrebian Region DOI: http://dx.doi.org/10.5772/intechopen.94739*

*Natural Hazards - Impacts, Adjustments and Resilience*

relatively very short period of time shows that the heavy damage caused during the succesive seismic events occurred in this country with intensities ≤VII (**Table 2**), have highlighted the inadequacy of each previous earthquake-resistant standard. All of them have been imposing more rigorous technical requirements and guidelines for the construction of new buildings and major rehabilitation works but have not prevented structures built under the previous rules from being exposed to the risk of collapse or seismic damaging. In addition, the rule currently in effect also do not guarantee the absence of damage to new buildings raised after the effective date

**(km)**

1950/04/04 03:06:22 433.000 −60.000 — VI 4.6 MD Teverga 1950/05/02 07:37:46 381.500 −13.333 — VI 4.0 MD Archena 1950/07/01 12:19:44 371.000 −25.333 — VI 3.8 MD Gergal 1951/03/10 10:38:26 375.950 −39.750 15 VII 5.2 MD Castillo de

1951/05/19 15:54:26 375.670 −39.170 19 VII 5.3 MD Castillo de

1953/09/28 21:41:10 411.333 −15.833 — VII 4.7 MD Used 1954/01/08 16:33:50 369.333 −38.833 — VII 4.2 MD Arenas del

1955/11/27 20:30:08 373.017 −24.583 5 VI 4.1 MD Bayarque 1956/04/19 18:38:54 371.917 −36.833 5 VII-VIII 5.0 MD Purchil 1956/04/22 15:56:14 372.800 −36.100 5 VI 3.7 MD Calicasas 1956/04/29 14:54:29 371.833 −36.833 — VI — Albolote 1956/05/03 01:03:43 373.867 −35.967 5 VI 4.3 MD Iznalloz 1956/05/14 09:57:32 371.833 −36.833 — VI — Albolote 1956/06/05 11:41:24 371.717 −70.983 5 VI 4.2 MD Punta Umbría 1956/08/16 02:09:40 369.100 −86.067 5 VI 5.0 MD Golfo de

1958/01/16 15:13:38 381.000 −0.6000 — VI — Guardamar

1958/02/05 10:18:25 384.583 −0.7350 5 VI 4.7 MD Petrer 1958/06/18 14:24:17 389.000 −15.250 10 VI 4.3 MD Hoya-Gonzalo 1958/12/22 02:48:16 381.833 −11.167 — V-VI 4.0 MD Fortuna 1959/08/23 22:21:30 355.133 −32.267 20 VI 5.4 MD Alborán Sur 1960/06/01 06:18:54 380.967 −0.9117 5 VI 4.4 MD Redován 1960/11/14 20:10:26 370.283 −53.283 5 VI 4.5 MD Pruna 1960/12/05 21:21:47 356.900 −66.217 5 VII 4.9 MD Golfo de

1961/02/10 18:52:01 417.250 −61.967 — VI 5.2 MD Zamora 1961/09/03 23:33:13 419.333 −20.833 — VI-VII 4.6 MD Aguilar Río

1962/05/03 23:27:22 438.850 −70.150 5 VI 4.3 MbLg Cantábrico

**Int. Mag. Epicenter**

Locubín

Locubín

Rey

Cádiz

del Segura

Cádiz

Alhama

of the law and only aims to avoid the immediate collapse of the structures.

**Date Time Lat. Long. Depth** 

**318**

#### **Table 2.**

*Earthquakes felt with intensities VI to VII in Spain between January 1, 1950 and December 31, 2019. Note that earthquakes of magnitude M < 5 can also cause effects of intensity VII in direct relation to the shallowness. Source: Instituto Geográfico Nacional (IGN).*

In Lorca, most of the damaged RC housing blocks had been built in three different construction periods: before the first anti-seismic standard of 1968, during the period from 1968 to 2002, and after 2002 standard, in use on the date of this earthquake. But none of these technical rules devoted enough extension to deal with the coupling conditions of non-structural elements, with the consequences that will be discussed below. The first RC housing blocks in Lorca began to be built from the early 1950s onwards, in a period of time marked by the international blockade and economic situation of autarchy (self-production) of the Spanish government after the Second World War. Faced with the impossibility of importing raw materials, steel rebars of low quality and scarce quantity were used for the two essential elements of RC frames: beams and columns. In fact, several patents were developed in Spain to create RC beams containing up to only two steel rebars [22].

However, although it seems difficult to explain, older RC buildings did not suffer a greater damage than those built after the 2002 standard. In **Figure 20** we can appreciate slight shear cracks in the façade of pre-1968 RC buildings, not showing apparent structural damage or deformations of RC frames on the ground floor, despite the lower stiffness due to the lack of infill walls (grade 3, class C). Paradoxically, in **Figure 21** we have the complete collapse of the four-story residential block mentioned above, built during the transition period to the 2002 earthquake-resistant standard. This means that improving rules does not always implies improving resistance.
