Thursday 13 September 2012

FORM-BASED DESIGN ASSISTANCE FOR HOPELESS PLANNERS AND HELPLESS ARCHITECTS

EN ESPAÑOL

Patrick Murphy is a member of the panel of discussion into the Special Session



THE ABSTRACT OF HIS PAPER: 


FORM-BASED DESIGN ASSISTANCE FOR HOPELESS PLANNERS AND HELPLESS ARCHITECTS



The 2011 Lorca earthquake confirmed once again the treacherous relationship between reinforced concrete frames and masonry infill panels. The city was left with many examples of permanently deformed ground floors, fragile non-ductile damage to ground floor column heads and shear-damaged infill panels. However, if these damage patterns are so well understood, why are they so recurrent?

This exercise explores how shortcomings in code provisions, hopeless planners, hapless architects, fractious developers and peevish engineers all consort to perpetuate risky urban environments. The paper concludes with a form-based design approach to assist in multidisciplinary earthquake resistant design education. 

DAMAGES IN THE BAROQUE CLOISTER OF SANTO DOMINGO MONUMENTAL ENSEMBLE IN LORCA AFTER THE EARTHQUAKES IN MAY 2011 (PHOTO ANTONIO ARETXABALA DÍEZ) 


ABOUT PATRICK MURPHY

PATRICK MURPHY
Patrick Murphy graduated as an architect from Canterbury and Kingston universities in the United Kingdom. Patrick has been active for many years in seismic engineering research, specialising in earthquake resistant design, vulnerability and seismic risk. 

He has co-authored the Seismic emergency plans for civil defense for the Spanish autonomous regions of Murcia, Andalusia and Navarre. Patrick is frequently on the field in damaging earthquakes in the Mediterranean region and a frequent contributor to field reports. He recently authored the chapters on building damage after the Lorca 2011 earthquake for the Spanish Geographical Institute's official report. 

Currently he holds the position of Director of Architecture in Broadway Malyan's Madrid office, a leading international design practice, where he leads large scale architectural and masterplanning projects in Europe, Asia and Latin America.


Broadway Malyan is a global architecture, urbanism and design practice. Distinguished by a global reach with 15 offices across world centres, unrivalled diversity with 500+ sector experts and distinctive client focus with over 80% of 2011 income from repeat business, BM create world-class and fully-integrated cities, places and buildings.

ITALY: 150 YEARS OF SEISMIC DISASTERS (1861-2011)

Weighing the economic and social cost of earthquakes 

An article by Emanuela Guidoboni for INDERC

Italy is an ancient country, but is politically young. It achieved unification only 150 years ago, first as a kingdom, then as a republic. In 2011, the one-and-a-half centenary year, a book was published that explored the disastrous chapter of earthquakes that have stuck the country in the course of its history as a unified nation. The aim of the book is to do some serious groundwork towards better prevention of seismic risk. Italy is the only high-seismicity industrialised country that has not made a concerted attempt to tackle the earthquake scenario. That there should be widespread awareness of the issue may be a first step. The authors of the book were Emanuela Guidoboni, a historical seismologist – coming from a historian background – and Gianluca Valensise, an earthquake geologist. Historical seismology in Italy is an advanced research area on which the Istituto Nazionale di Geofisica e Vulcanologia has been engaged for decades. The data it yields are crucial in calculating the parameters of past quakes and assessing the hazard status of an area or site.

DAMAGES IN THE RICH HERITAGE OF ITALY
Geologically, Italy has had the same seismic profile as now for millennia, an expression of its complex geodynamic history and the life of Earth itself. In fact, the seismic hazard of a territory is by definition ‘stationary’: it varies little in thousands or tens of thousands of years. 

What does change over the epochs – and greatly so – is the seismic risk, since the pattern of habitation in such areas changes (the demographic density, the amount and quality of buildings). What impact have Italy’s major earthquakes had since the time of unification? 


An enormous impact in human life, loss of property, abandonment, emigration, and long and costly reconstructions, often not brought to completion or simply shirked. There have been about 150,000 deaths (an average of 1,000 per year, though they bunch together into a few seismic catastrophes), although Italy’s level of seismicity is lower than that of other Mediterranean countries like Greece, Turkey or Syria. On average Italy gets two or three magnitude 7 or larger earthquakes every century. Yet in the history of the past 150 years there was 34 seismic disasters, meaning earthquakes of high destructive impact, such as all those in the magnitude range 5.8 - 6.9. The twentieth century brought two earthquakes exceeding 7 M (1908, Messina Straits, M 7.1 and 1915, Marsica-Abruzzo, M 7.0), but on average there has been a disastrous earthquake every 4-5 years. In all, there has been significant damage and destruction in 1,560 settlements, including 10 main towns. 


DIANO MARINA LIGURIA, 1887

Besides these 34 disasters there have been 86 lesser quakes, though their effects were not much lighter than what the authors term ‘disaster’. Bracketed with these there are major flooding and landslip events. And let us not forget two World Wars. All in all, a chapter of history bristling with tragedy (but the Italians are ‘resilient’ people!). The worst earthquakes in Italy are bound up with the dynamics of the Apennines, that still youthful mountain chain running full length from Liguria to Sicily. Epicentres tend to lie along the Apennines ridge and hence strike mountain and hill centres much more. 



So much for the main seismic area, but there are secondary areas that are not a bit less dangerous: indeed, the seismic risk is much greater since these zones tend to be more built-up and productive. They include the Alpine foothill belt in Veneto and Friuli, western Liguria, a large swath of the Po valley, the Gargano and Capitanata (both in Puglia), eastern Sicily and parts of northen and western Sicily.

Clearly the relationship between the energy released by an earthquake and its surface effects depends largely on the housing pattern and the quality or vulnerability of buildings involved each time. As the authors tried to point out, the vulnerability of Italian building is due to various factors, the main being the widespread poverty in rural areas and small townships, especially in the central and southern parts of the country. But vulnerability factors include also the decadence of traditional building techniques and the huge number of architecturally valuable ancient monuments which have never been properly protected from such risk. Another important factor is contemporary building negligence (witness the industrial buildings affected by this latest earthquake, Emilia 2012), and the low quality of public buildings, ancient and modern, which really ought to be closely monitored and rendered safe. Another point is the site of construction, often inappropriate since already impaired by landslips that get tragically re-activated in an earthquake, or on soft or unstable ground that causes amplification of the ground motion.

CALABRIA -SICILY TSUNAMI 1783

The book presents many photographs: it forms a valuable data store, ruthlessly chronicling the heaps of rubble, loose stones or strewn cubes of tufa and houses dissolving into dust. We see floors that have fallen through, resting on unduly thin beams, already misshapen, hardly anchored at all to side walls that can barely support the weight of their roofs. To the experienced eye our pictures also reveal the dismay of survivors surveying the rubble-heaps that were their homes, streets and squares all out of kilter, signs of social life at times obliterated for ever. The rubble mounds spell a waste of previous toil and new labours to be endured ahead in the solitude of depopulation.

We can but wonder why in these past fifty years in Italy – those of the cultural and welfare boom – there has been no broad concerted reaction to the earthquake effects. This should be a vital part of national culture, such as other developed countries have witnessed wherever the earthquake risk was high. One can hardly lay the blame on lack of economic resources and materials, as was the sad case in the last decades of the nineteenth century and the crisis following World War I, which stretched from 1915 to around 1930. One is forced to conjecture that other factors are at work. One is struck by the persisting short-sightedness of territorial planning – just where decades of stable forethought might be expected to tackle environmental hazards. There has been and still is no shared awareness of housing safety.

LA ROCCA (FINALE EMILIA, 2012)
Alarmingly, there has been limited let-up in the seismic disaster pattern even during the past ten years, as emerges that even low-magnitude recent quakes have caused serious damage. This chapter of seismic disaster highlights the repeated weakness of institutions in applying norms to protect the building heritage, whether monuments or private homes - though rules and laws have proliferated on paper in the course of the years. The chief weakness to come to light is the failure to check up on construction quality. This has become tragically evident where relatively smalle quakes have nonetheless brought destructive consequences. 

All seismic risk countries know that applying the anti-seismic laws is a basic step in making buildings safer. It is also well-known that such rules can only be concretely enforced when the people involved are informed of the risk they are running and are prepared to adhere scrupulously to modern techniques of risk-reduction. The latest earthquake, Emilia 2012, struck the population and local administrations like a bolt from the blue. It shows how woefully seismic maps fail to convey the risk to the population and decision-makers alike. We still have a long, long way to go.

Saturday 8 September 2012

TWO HISTORIC EARTHQUAKES: LISBON 1755 AND CALABRIA 1783

Emanuela Guidoboni (SGA Geophysical Society-Environment, Italy) debate here about the Lisbon earthquake of 1755 and the earthquake in Calabria in 1783. Both earthquakes were of high intensity and were followed by tsunamis that significantly increased the high damage and loss of life. However, these two disasters were responsible for the beggining of the major building systems in the world of the eighteenth century with anti-seismic concerns: Gaiola Pombalina e a Casa Baraccata. Nowadays both building typologies are at risk to preserve their identity. The lessons that can be drawn from all historical earthquakes and the effects they can have in building activities, form the basis for preparation of cities to improve their seismic-resilience. These will be the aspects debated and discussed.



Less than thirty years after the Lisbon catastrophe, the centre and south of Calabria was struck by five devastating earthquakes between 2 February and 30 March 1783, reducing the area, in the description of contemporaries, to “a heap of rubble”. The destruction extended to Messina (Sicily), at the time an important trading centre. Historical research from the archives has brought to light the seismic areas activated and the whole scenario of effects in urban centres and villages, as well as the natural environment (landslides, fissures, liquefaction phenomena, the creation of new lakes and complete re-routing of rivers). 

ENGRAVING SHOWING "O TEJO", THE MOUTH AND THE TSUNAMI, LISBON 1755 (WIKIPEDIA)
This highly complex seismic sequence also caused a tsunami in the Straits of Messina. Aftershocks in their hundreds went on for some four years. Such a sequence nowadays would be devastating in its impact, given the demographic density and the poor quality building of modern Calabria. The entire area thus stands at high seismic risk. Portugal’s 1755 experience was partly drawn on when it came to designing new housing in 1784 (from the gaibola to the casa baraccata).

New Calabrian townships were designed to a regular grid plan with broad streets and low-rise buildings to increase seismic resistance. New building regulations were issued by the Bourbon government, but then not enforced. A decade later in 1799, the anti-Bourbon uprising overthrew the government: amid institutional weakness and political/social strife, the anti-seismic project fell into abeyance. A kind of amnesia descended on the earthquake issue, for which later generations would pay dearly when quakes struck the region once more. Historical analysis of this crucial seismic sequence embraces scientific, townplanning and cultural aspects of this disaster.

VUE DE L'OPTIQUE COMPOSITION (HAND COLORED COPPER ENGRAVING USED IN THE LATERNA MAGICA TECHNIQUE) SHOWING SEA SHIPS AND BOATS ENDANGERED IN THE ROUGH WATERS OF THE MESSINA STRAIT DISTURBED BY THE 1783 EARTHQUAKE. FROM HISTORY OF GEOLOGY

After the 1755 disaster, the Calabrian earthquake fired European awareness of man’s risky relationship with nature and prompted scientific debate as to the causes of earthquakes and their relation with habitation patterns. The event seared the entire Bourbon kingdom of Naples; and with it the whole late-eighteenth-century spirit of Europe. That long seismic sequence in Calabria was made up of five violent earthquakes. The devastating impact marked an epoch in the region’s economic, social and cultural life. On February 5th 1783 a series of tremors began that would last more than three years. The five peaks of maximum intensity came on February 5th (M 6.9), 6th (M 6.2), 7th (M 6.4); and March 1st (M 5.6) and 28th (M 7.0). 

These five quakes were preceded and followed by several hundred lesser tremors – at times hardly lower in force. The cumulative effect of this seismic upheaval was to destroy thousands of square kilometres of territory. The destruction extended from Central Calabria to Messina (Sicily), at the time an important Mediterranean trading centre. Historical research on administrative documentation (State Archives, Catanzaro and Naples), letters, reports, field reconnaissance and treatises, has pinpointed the seismic areas activated and the whole scenario of effects in urban centres and villages, as well as in the natural environment. In less than two months a number of North-South oriented faults became active along the Apennine chain. 

Destruction was almost total in 182 villages (X and XI MCS), and in 33 of them the decision was to rebuild on another site. Some 300 other villages suffered serious damage and destruction (from VIII to IX). In the worst hit areas there were over 35,000 victims out of an overall population of about 400,000 (about 8% of residents). The earthquakes of 1783 shook an already precarious social order to the core. Infringements of law and order, dearth of housing and galloping epidemics were accompanied by a general conviction that a point of no return had been reached. The impact on the natural environment was so direly spectacular that scientists and naturalists of the day flocked to take note. 

Landslides and slips, fissures and cleavages, newly-formed lakes and liquefaction phenomena were, for the first time, mapped and drawn as scientific documentation (the Schiantarelli e Stile Atlas, Accademia delle Scienze e Lettere, Naples, 1784). A far broader area was involved than the epicentres of the worst quakes. Whole hills slid into valley bottoms, sometimes dragging settlements with them, and blocked waterways, creating several hundred new lakes. On the night of the 5-6 February 1783 an enormous landslide crashed into the Tyrrhenian Sea near Scilla: waves of 6-8 metres in height struck the Calabrian coast and swept inland more than 160 metres, bringing new havoc and another 1,300 deaths.

ENGRAVING SHOWING THE 1783 CALABRIAN TSUNAMI (WIKIPEDIA)

The toll of this seismic cataclysm was not just villages, but urban centres important to economic and military life in the Kingdom of Naples and Sicily: towns like Reggio Calabria and Catanzaro, as well as Messina. The all-extensive desolation of Messina was described some years later by Goethe in his “Travels in Italy”: he called it a city of the dead. The extent of the area destroyed, which included some small relatively productive centres embedded in a large backward hinterland, prompted the central Neapolitan government to intervene. 

Normally after a violent earthquake it would simply grant a few tax exemptions – unlike the previous Spanish government which set in motion a great work of reconstruction in eastern Sicily following the 1693 earthquake. The 1783 disaster was at once taken as an opportunity to try and redistribute resources, above all land ownership, and plan new towns and habitation patterns. The experience of Portugal certainly influenced these decisions, with her reforming drive to rebuild in the wake of 1755, powered by a flourishing mercantile economy since Lisbon was the capital of a colonial empire. But where were the funds to be found for Calabria, an outback of the Kingdom of Naples? In June 1784, spurred by Minister Caracciolo’s reform project, the Bourbon government launched a complex process of widespread expropriation of unproductive land belonging to the Church in Calabria. 

These and certain baronial latifondi were impounded by a specific office called the Cassa Sacra. By administering and selling that patrimony, the government meant to finance the reconstruction of villages and also reboot the Calabrian economy via land redistribution. A new phase of development was envisaged for areas that had been marginal to the Kingdom’s social and economic life for centuries. New sites were chosen for rebuilding, townplanning projects were commissioned. The new plans make interesting viewing: they are star- or grid-shaped, with broad streets and buildings designed to dimensions and a regular pattern never seen before in Calabria

On the model of the Portuguese gaiola which came in after the 1755 disaster, a version incorporating a few variants was proposed: the casa baraccata, designed on a wooden framework with infill panels. Unlike the gaiola, the casa might be several storeys high and form part of the urban fabric. But after a few attempts to promote it, it was deemed an oddity (the prevailing building style in Calabria was stone or unbaked earth): an unduly expensive piece of modernism, the project was dropped. The bid to make good the laceration of the social and housing fabric fell short of expectations. Intellectuals and reformers of the period identified the causes of the widespread backwardness and poverty: 

i) lingering feudalism: 83% of Calabrian territory was under baronial power; 

ii) absentee landlords neglecting economic and production problems; 

iii) a rapacious central tax system; 

iv) state weakness vis-à-vis baronial and Church power;

Such factors were not removed and within a few years the newly-launched reconstruction scheme had failed. Only four of the many new towns intended were actually built. In the years that followed, another feature was exodus from the land towards the bigger towns. This only worsened an already severe shortage of labour on Calabrian farms. At least down to the mid-nineteenth century, the lost lives and crippled socio-economic life of Calabria due to the 1783 earthquakes made the region’s demographic development lag behind the other regions of the Kingdom of Naples. 

The direct and indirect impact of that long seismic chain brought crisis on the manufacturing sector: the wool and silk industry at Palmi was sorely hit, and an epidemic of fevers set in on top of the earthquake. At Pizzo relatively few died under the rubble, but an ensuing epidemic caused many deaths among those camping on the beach for shelter. Some places, like Seminara, Oppido Mamertina and Briatico, suffered a recurrence of the fever epidemic in summer 1783 owing to malnutrition, poor hygiene and the prolonged privations. This epidemic alone caused nearly 19,000 deaths. A decade later in 1799, the anti-Bourbon uprising overthrew the government: amid institutional weakness and political/social strife, the anti-seismic project fell into abeyance. A kind of amnesia descended on the earthquake issue, for whicwhich later generations would pay dearly when quakes struck the region once more.

MESSINA, 1908 AFTER THE TSUNAMI, HISTORY OF GEOLOGY

Tuesday 4 September 2012

A SEISMIC AMNESIA




The history of Spain (excluding the 130-year period immediately preceding modernity) in the last seven centuries is replete with examples of destructive earthquakes with intensities above VIII on the Mercalli scale (above 5-6 on the Richter scale). "Earth tremors" and what to do if they occur, were subjects of study in schools and universities until a hundred years ago. The culture of the seismicity is a phenomenon that has not been updated as other aspects of the country have been, simply forgotten.


PUBLISHED IN ABC AND OTHER JOURNALS
RELATED WITH:



COLLAPSED BUILDING IN CAVEZZO, MAY 29 2012


1. INTRODUCTION


When I published my article, "A Seismic Amnesia", in ABC and other journals, I received several comments from colleagues and friends, among them geologists, architects, engineers, professionals from the world of communication, and more. Most encourage me (despite precisely such amnesia and the increasingly scandalous lack of resources) to continue to promote the investigation of these phenomena in relation to the distribution of territory, knowing a priori the characteristics of the land where we humans decided to establish our habitat, residence, work activities, etc. Urbanism and seismic microzoning have gone so far in Spain on opposite paths or, at best, parallel ones, that they almost never touch, and it has brought us, and, it is sad to say, will bring, injuries, fatalities, misfortune and suffering as it has to those still living in Lorca.

Resilience through culture is avocated in this blog as one of the most effective tools to overcome adversity after natural disasters or even those disasters created by us. Architects and planners still have much to offer and contribute to this "ground", although many are not aware of the huge field of professional activities that earth sciences will provide architecture in its growth, especially in this new century, and especially with the emerging interest (and need) to look back to our heritage and its new physical contexts and uses, both of them have changed.

Of all the comments I have received, I want to highlight those of Manuel Fortea, architect and doctor of art history, plus, great expert, connoisseur, and keeper of our heritage treasures, so often forgotten and abandoned. With permission granted, I step to translate this article in its deeply pedagogical comments and thoughts, words that are the vehicle of a culture, sensitivity and wisdom especially needed in our society, especially in these times so lacking in brilliance and full of pride and speculation. It is an honor for me that it may appear on this blog, as a master class that gives us an invaluable gift for its high technical value, but mostly its human one.


Loredo, Cantabria, june 2 2012
Antonio Aretxabala Díez    



2. THE WORDS OF MANUEL FORTEA:


The first sentence that I tell my students at the Ecole Polytechnique of Extremadura (formerly Technical Architecture, Building Engineering today, and tomorrow we do not know) in Construction class is: "Do not forget that Nature is working permanently (24 hours per day, 365 days a year) to destroy what man builds to return everything to its previous natural state. Sometimes it's a low-level job as rain or frost or other times an action as virulent as lightning or earthquakes.

Indeed the memory of man retains these issues beyond one generation. We still believe that the walls of Jericho collapsed by the sound of trumpets, denying that the noise came from the womb of mortal soil accompanied by a jolt.

Our current building technology (reinforced concrete) is barely a century old. A life too short to evaluate the final balance in his enduring struggle against Nature.

Personally I think attempts of prevention of the effects of natural phenomena on the human population come closer to respecting Nature, than those of legislation "against it". When a man's ignorance is compounded by arrogance, failure is guaranteed. The best way to prevent the destruction of a flood is to not build on the riverbed. The best way to minimize the catastrophic effects of an earthquake is to not build at critical points, at points where nature dissipates its internal energy. No cook would think of putting a finger over the rising steam from the pressure cooker. Most importantly, the cook would the location of those valves. Information that applies to any culture and any historical time. Again, the best prevention against seismic effects is a detailed geographical map subsurface of geological features, an x-ray of the soul of the earth. Any attempt to believe in power to conquer nature in these battles is simply an act of ignorance and arrogance.

In order to design a building able to withstand the impact of an earthquake in a scientific way, baseline data are necessary: Exact location application, released energy, duration, frequency of vibration, movement distance, number of replicates, etc. In short, unobtainable data. Can you imagine an engineer designing a structure that had to withstand lightning and voltage whose maximum temperature could not to exceed unknown values? Simply stupid.

Just after the earthquake of Lisbon in 1755 the Marquis of Pombal (Portugal Head of government) was asked by his advisors "Mr. Marquis now what do we do?” Undaunted and secure he replied: "Bury the dead and take care of the living."

An appropriate and timely article, it demands repetition, slowly, to all those responsible.





The replicas, an average of one every hour, numbering in the hundreds, in the north of Italy, some of them over magnitude 5.

EPICENTRES IN RED 

Sadly, yesterday the body of the 23rd confirmed victim was found, trapped in the rubble of the recent earthquake. Six died on the 20th, and seventeen on the 29th. Aftershocks occurred at an average rate of one per hour, numbering into the hundreds, some over magnitude 5. The Italian earthquake resistant construction standard of 2004 did not yet take into account the seismo-genetic character of these dormant-faults for 450 years. The seismic memory of the people of Emilia Romagna has suffered four centuries’ worth of amnesia and tremendous human losses, as well as social, economic and cultural ones. Ferrara (World Heritage Site) the first modern city in Europe, designed urbanistically already in the fourteenth century, was made taking into account such a well known phenomenon. The more we know about these new Italian earthquakes in their scientific aspects, the more they resemble those of Lorca in 2011, and less those of l'Aquila 2009.

Active Faults are implicit in our Spanish Seismic Code (NCSE02). Those that are not considered active are not present. The first type of faults affect a total of 2618 sites located in areas at risk from earthquakes, 724 of those sites assemble more than 5000 inhabitants, a population of over 20 million people. Of the second kind of faults we know almost nothing. However, despite Spain being a seismic country, there is no historical consciousness even in scientific circles or in the bulding sector. It has been almost 130 years since the catastrophic earthquake of 1884, called the "Andalusia earthquake", caused about 1200 deaths and destruction that came to Grade X. This long span of time has contributed to ​​our Spanish Seismic Amnesia.

SEISMIC RISK MAP OF SPAIN

During this time we have tripled as a population; we have gone from about 16 million people living mainly in a rural setting, to 47 million predominantly urban and with high mobility. Therein lies the greatest danger, and much more now than before. The best weapons to successfully overcome earthquakes, we have them, but hidden away, the Advanced Land Law of 2008 is tucked into the drawers of regional autonomies, but almost nobody knows of it, this is our amnesia. The general public would not know how to react to facing an earthquake; worse, they don't know the most seismic areas of the country itself: the most crowded.

Moreover the population that is the most specialized, or even cultivated in seismic topics, is believed to be the engineers and managers those responsible for disaster mitigation through implementation and enforcement of standards and codes that are increasingly sophisticated. Engineers also believe that they are designated to lead us toward that end by applying theoretical postulates that nature always exceeded, the object of their studies: buildings and structures, i.e. the parts of the system. But the real earthquake scenario is the twenty-first century city. Earthquake resistant building standards have not been, are not and never will be enough. 

Spanish cities are designed with zoning laws inspired throughout the twentieth century (including any individual interest or speculative) criteria least earthquake-resistant design. The reality is that the history of Spain (excluding the 130-year period immediately preceding modernity) in the last seven centuries is replete with examples of destructive earthquakes with intensities above VIII on the Mercalli scale (above 5-6 on the Richter scale). "Earth tremors" and what to do if they occur, were subjects of study in schools and universities until a hundred years ago. The culture of the seismicity is a phenomenon that has not been updated as other aspects of the country have been, simply forgotten.

The seismic amnesia of the population, media, and leaders, seems to predominate over the sporadic outbreaks of interest when something like Lorca or Ferrara arouses curiosity and makes us think of the country and its earthquakes. In these times the bars are filled with expert geologists, architects and engineers. Then time passes and the country sleeps again.


THE ROLE OF MEDIA FACING DISASTERS