eSigning Pooling Agreement Made Easy

Esigning pooling agreement

so talk about the which was a very important offices the nineteen eighties topic is not the most research analysis good morning everyone it's a night for me to be back in Hong Kong once again the first time I came here the Bank of China which you would see on the additional slides or I think one cross hi so I have my physical problem I'm gonna talk about the progressive perhaps I could talk about it in a very general sense now for people of my anguish we were supposed to know where we were when we heard about the assassination of President Kennedy in Dallas in the United States very 2001 another event occurred where I think most of us in this room will recall how we heard about the collapse of the World Trade Center in New York and he has played out on the Tonys and screams of billions of people across the world helping these iconic buildings designed by one of the world's great knuckle engineers their water collects in front of our house well some 50 years previously another incident where the USA is playing became disorientated in locale and crashed into the Empire State it did relatively didn't damage the building was subsequently repaired and the Institute was really lost in history and too was resurrected in the wake of the World Trade Center what was it that that incident produced a repairable situation where's the World Trade Center they into spectacular collapses that's been the subject of considerable interest to start engineering profession over the past 20 years or so let's go back into history the Eiffel Tower is important bills line it has all the characteristics of a steel structure and it's important because at the time mechanics was strong in France and this is one that there are structures worldwide debating from some scientific calculation determination of the internal forces for Geneva members to take events over some 50 years previously Robert Stevenson the well-known rare engineer who designed the britannia bridge which is the one in the ballroom the bridge in the background is actually suspension bridge designed by i was told the best president of the institution of civil action aims the bridge of the front is actually a modification of the original because in 1976 which was notable in Britain because it was until this year the hottest summer on record and the bridge was damaged by a fire on the girder and in rectifying that the opportunity was taken but the President believes would have broke over the top but the interesting point to note here is these towers and the ports that were originally derided the house suspension cables of the sort that we see in Telford bridge because the engineering community of the dirty fell it was impossible to spend that sort of distance without suspension cables the Stevenson was position he went to two professors of London University Airmen and Hopkinson one an expert in mechanics one an expert in materials and through a combination of laboratory testing and calculation they were able to demonstrate that it wasn't impossible to spend this business and this is a very early illustration of the direct use of up-to-date knowledge and research findings in actual construction to react a substantial change to the prevailing wisdom of the time throwing science nowadays is whether the husband has places it was always sunshine in the Middle Ages in countries across Europe cathedrals were built and each one was a little bit more adventurous for the previous one and it collapsed nobody much knew about it because it was no internet no see any growing news and the designers of the next one will be a little bit more conscious then we have science mechanics to underpin the design of structures and we have a series with different design approaches the better recent of which is the so called performance base that comes from the seismic community but most of us are still working within this space designed and recognized two conditions he also had limits paid the maximum over the structure intake and serviceability frequently observed overs which should not impair the performance of the structure vibration of the floors in a building for example and we all know illustrations of where this goes wrong this is the North attained in breach of safety wirelessly Britain it was my first involvement in an academic consulting job to assist by then PhD supervisor in trying to help the British Ministry of Transport and to spend quite what happened in that structure and it was in fact relatively straightforward to work out that the diagram was under designed because it was just too adventurous at the time we didn't know as much as we thought we knew the result of that an enormous research not just in the UK but also in Germany in Australia because of the Westbank plants and indeed in the United States as well that put this subject on altogether different foot serviceability frequently it's about the maximum deflection structure to take and push it depends on circumstances here we see the poor ground the German farmer in the cowshed with some looting stories and if you talk about his head their story whereas a penny on top of these early members and in channel sections of a rich beaver that them rotating through 90 degrees and the structure is effectively being held up by these same files retracting this as ties to provide a two-way spanning arrangement if we go back this Chinese are concerned about what's happening because it's only caps underneath and the consequence is you are not that severe so serviceability is very much of the prevailing situation and we would devise the way you are trapped engineering a painting conventional structure design for snakes representing the loans do some analysis which narrates be choosing computer software deciding on the suitable acceptance criteria and in comparison the revision to see if we have the designer and the design to refine the design and that works very well we can do recognizer and 200 different panels 90 60 1800 already living on the 18th floor of this 22 story precast concrete system the building of apartment produced in the aftermath of the Second World War to provide housing in London to replace that that was destroyed due to the arrangement so-called she got she is a match there was a gas explosion it blew out the corner of that structure subsequent investigation showed that the pressure generated by the explosion was about the same as in three meters of rooms in other words the deep end of a swimming pool not a very severe test an important structure there not been designed to take care so in fact it was not very well constructed either it dates to the moratorium on casting high-rise buildings and to the appearance of new terms of the Pope a Prius truck French means progressive collapse disproportionate grass grow massless how do we deal with those sorts of topics there is a government inquiry there is a publicly available report published and accommodated with some recommendations on how to deal with this instructions the types of public buildings of other types of ports of attraction this is the very bell ringing Oklahoma City United States this was a result of damage of the Great Hall and was World Trade Center where we saw buildings the top left hand corner hit by the aircraft reduced to the problem that we see the bottom right hand or mice actually fortunate to be able to visit the site shortly afterwards and that part of rather you can see on the bottom right corner is actually a good woman he's ever story building renovation survey theory in the early part of this disability we sent out a small research project to try and understand what it was that control robustness progressive tension progressive collapse in speed structures and we looked around for information and assistance from the history of crunch engineering not yesterday progressive collapse because there's so few incidents is by definition a rare but high consecrates phenomenon so we don't want we want that majorities in central London and it's just as you mention is has a very comprehensive record with this publication and we can see here what we call conceived reaction where this was obviously a bleep but because it's that we have separated from the column this is directly more painful through the enormous dimensions of not twice the depth of the structure that maintaining the intake integrity of the structure my conceived reaction or something like that be important to resisting progressive collapse is a where we can see notice decorations and the ductility able to observe the forces from the fall damage and again no separation of the structure so we can see two or three detention features here that might be important in understanding how to address progressive collapse but then thirdly this is a earthquake community in Mexico City we can see some evidence of the activity here energy absorption through declaration and again despite the damage with the broad beans have not become separated from the columns and so the structure has not actually collapse so from this we decided that there are a number of physical features of grupo in understanding the mechanics of progressive collapse in Hammonds bakery is a dynamic occurrence so static analysis isn't going to work what's crucial and what differentiates the impossibility of the World Trade Center was the ability of the damage structure to capture a new equilibrium position and to remain sane what support of that dramatic separation of the components so the connections between the beams of the penetrates often a regular building structure our pleasure in resisting progressive collapse and what sort of phenomena are mobilized well roast equations we saw the bomb damage building in London we don't know perfections of beings being twice the depth of the being there were small fraction and create these very nicely it has to be hey government declaration and so we also the same subjective mind that we wanted the emotion we would devise to progressing progressing perhaps too similar to the energy engineer to conventional structure design similar seven calculations or similar process similar value would work and not to be something that was available only to a very few experts usually very sophisticated techniques there are from the random inquiry report we can identify three potential approaches time forces alternative paths of key elements and Nathalie because we like probability of statistics of risks and so on we would introduce that into the framework for assessing progressive collapse influences time poses really say that if you tie the building together by having it's really intense our resistance in the connections between the pins and the columns that were better than if you don't it's qualitative there is no mechanism for using this direction compare one it's our fault with another so it's just Utley it's better to do be more robust if you do TLC we see action is the bar situation where the top row Commons architecture of about art and we could see the quantum protect even perform better at the fire in destruction so we could design certain key elements to have a greater margin of safety again it's an approach tanks burger the streets offering buildings like to tell people that's patented that of course but probably the most efficient of these are so-called internal load bars which really says if we measure a component remove the column as shown here is the remaining damage structure able to bridge across there and obtain any predict through position that maintains the integrity of the structure that's have been also analysis now conferencing the United States in San Francisco just over 10 years ago and notion American researcher work at many years of the National Bureau of Standards in in the US state was virtually no research in the u.s. even progressive perhaps well alternatives right in this situation changed policy with groups most countries around the world actively investigating this I got the power we producing this art assuming that this was done with some sort of ruler so then actually this line top again but it's all to do with the surgery it's not a sudden reduction in the interest in something I don't believe that's happened so current research around the world really into three categories numerical analytical risk to the probability which is more we're looking at the problem of what I call target which is really focusing on aspects of the problem apparently we have enormous computing back in the way of the World Trade Center collapses National Bureau of Standards stone in the United States book the largest computers they had to work on numerical simulations of what happened some of these browsers lasted for weeks and you've got one results so it can be done but it's not a very practical approach thinking in terms of green engineer mr. probability branches gives us ways of thinking is how do we deal with these high concentrated load probability events what what's the right approach to taking discipline the priority research here we see on topic testing USB Austin Texas in the United States and writer in Belgium try to understand dental mechanics of progressive collapse of the various components and you can see on the right-hand side once again we have to think of different forms of testing because we think never completely different regime enormous directions in the structure so we go back to the design of the piece for the design approaches to the site we've seen before and in doing that they can happen we catch the outcome from our research into a similar sort of process so we hope to simplify the problem if we imagine a brain structure we removed one column here and you know the ability in this data structure to all the new equilibrium position well all face up that been behaving a certain fashion so we can isolate that power structure we even then look at the typical floor and examine that in terms of behavior individually most retention is a lot more comfortable dealing with individual beings than they are complex nonlinear analysis of three-dimensional the returns of work in theatres and here we see what is key to understanding business is vertical blows against vertical deflection for a single B now we start with linear elastic behavior that's really multi working in rural structures and then we get to open the laundry say this is from maximum load ultimate limit state of collapse but it's best we keep going there is the enormous possibility beyond and eventually this line starts to rise as routine reaction starts to happen now it may not be possible physically in the structure because with enormous defections our own declaration capacity key components but what we see here is the ability to analyze like that was viciously variable but one of our federal research students reconfigured the traditional slope deflection equations each one all that we recognize the additional features and the comparison theories we've adapted in the analysis we have the words of select operation these we can do hundreds of calculation almost instantaneously because it's explicit expressions and aspiration but very easy to examine lots of cases so we did know all - what this is the context release correlation of structure and we devised this robustness assessment framework was recovering from the TV people college restaurant facilities in the audience was one of the epidemics was also great lunch involved with that bringing his expertise from the seismic site to address this also as a visiting professor of the numerous sites oh yeah complementary expertise and the key features really garden there's no time analysis required because as easily was able to devise a very clever energy balance method which meant we could revert the results of a spamming analysis into a dynamic response without doing any violence in the calculations we can were that the substructure British there also were calculations wandering it improves always you could stop when your phone is satisfactory right in between that separation the connections and expressed by existing that they're so exhausting the declaration acity or key component in that connection so understanding what's happening there we can make quantitative comparisons is you may better than Sweeney is he made should say every revised downwards that it needs to features in its own and it's very grateful to so initially were working with the Ericsson consulting engineer service temperatures also PhD student working on this and they have struck from the design companies a bit odd in the use rather heavy beans and salt that they asked us to use this as a model tracking example and so there were two scenarios music called economy and losing a problem and just into a flavor of some of the findings five cases here the first of all all three three throws as composit and the joints as policy the port of entry to the space new universe the interesting features on the extreme right hand side which shows that there's new place it's nowhere near supportive of necessarily only largely because of insufficient rotation of students and lower capacity in the student will steel connections as we put in more reinforcement where we resist pulling of the structure we get improvements of the consequence as you can see are more or less okay we also limited the correlation time capacity is that the main way to don't okay Vermont time resistance in the beads occult connections but we see here resistance to progressive collapse against the time resistance provided by the connections and I don't think there's much correlation you can see similar tying resistance back to what June aha also up in terms of persistence of progressive collapse alternatively you can get the same sort of resistance of progressive collapse by dumping point important evening time systems we now know that because we put a small temporary that there is a subtle relationship between aspects of what controls behavior of the connection tiger systems of resistance of progressive perhaps and it's more sophisticated that just time resistance and so and here we see the low Direction behavior what the theme this will be a normal linear elastic behavior a weak brain for identify different stages where different physical mechanisms pain to play to provide resistance and if we get to this point then we're into this gene research but we need enormous connections to get there and the majority three practical cases the physical connections power support the amount of rotation that's needed to get to that stage so in principle petunia reactions that's attractive that actually achieving it is somewhat typical we also have a hundred that the forces in a typical connection which really designed for any moment only that's additional power but then we get progressive force and the end up a lot of time forces almost remember to the connections are actually required to resist a very different set of forces in a progressive collapse situation than those in which they're designed under normal gravity move low and even religious here we take out if economy rules basically opposite we could told us the arrangement so but we could do these calculations very quickly upon that we could build up a picture of one of these that impressed me controlling things most of the work we did was dealing with frames that persistent horizontal loading due to the stiffness of the course but we also looked when the frames behaviour rather different thank you mrs. taipe used to the United States personal three strategic Joost activity also it's common practice there to leave this corner column protein to avoid introducing bikes who may become the seismic action that's actually a very bad teacher when we look at progressive parameters of your on a weakness in the structure and we can contrast in a simple way so for simply design frames and lower grades and seeing what the best sort of intervention is in each space to improve resistance so in summary as a result of the not programming every search that might be increased you so you have got to be expensiveness in terms of the university research we could summarize here and the conclusions we now have a situation with concern is heightened but there are ways without going into complex nonlinear numerical analysis to actually understand what that's designed to provide great resistance to progression perhaps but then I like clothes and thank you all very much