IPENZ(新西兰工程师机构之类的)关于这次基督城地震的信

mandy0512

From: IPENZ Chief Executive [mailto:postmaster@ipenz.org.nz]
Sent: Tuesday, 1 March 2011 4:26 p.m.
To: xxxx
Subject: Christchurch Earthquake Update



Dear xx,

Over the last week, IPENZ National Office staff and Members have been fielding queries from media and members of the public about the impact of the Christchurch earthquake.

As engineers and particularly as members of the professional body we have a responsibility to share the facts. However at this early stage, offering anything other than generic comment is not practicable.

For those of you who are concerned about rising levels of speculation and want to say something in your own community the following may be helpful

• It will be some time before conclusions about quake damage can be drawn on the basis of engineering analysis.
• According to the Department of Building and Housing the Building Code is based on the kind of seismic event expected to occur every 500 years or so. The Christchurch earthquake may have been as much as three times this.
• The New Zealand Building Code is in line with International best practice. It is continually revised and improved, however it is not retrospective, therefore, on the whole, newer buildings in Christchurch performed much better than older buildings.

Once again I offer thanks on behalf of the governing Board and Canterbury Branch to those members who are aiding the recovery efforts.

Dr Andrew Cleland
Chief Executive

mandy0512

概括成一句话就是，这次地震是的各项指数，是新西兰建筑标准的参考指数（参考指数是500年一遇的破坏性巨大的）的3倍，房屋倒塌是不可避免的，新西兰的建筑标准依然是国际上领先的。---我不是学结构的，翻译的可能很奇怪。

Devourment

3倍那就是1500年一遇的了= =（跑

greentree

这次的地标加速度市中心是0.78g，但是设计规范是0.22g，9月份的是0.26到0.28之间，所以破坏已经超过了正常的设计范围了。我知道这么说大家还是觉得很难受，因为没有人愿意看到有人遇难，自己的房子没有了。就想说，因为地震和强风都是没有规律的，没有一个地震的数据时类似重复的，所以我们所运用的设计值是在危机分析的基础上采取了一个安全设计的区域来进行的，这个设计值一直都是在继续更新的，在美国的地震中心，日本的兵库地震研究所，新西兰的坎大地震实验室，意大利的玫瑰大学都是在共同研究，推进这个理论，希望可以找到一个更合理的设计范围，能最大可能的保证人生财产安全的同时，也要达到一个经济效益的建筑。用个不恰当的比喻，出门被天上掉下来的石头砸的几率是存在的，但是却不是每天都存在的，所以不能因为这个较小的几率而不出门，只能做好一定范围的准备去防备这种存在的可能。

steven888

晕，专家啊！！！！！！！

la_ka

最大那个G是2.2。。。。。MGD

tjxxk

4楼很专业啊！

小拖泥

嗯所以说还是1500不遇的

mandy0512

http://en.wikipedia.org/wiki/Peak_ground_acceleration

Peak ground acceleration
From Wikipedia, the free encyclopedia

Peak ground acceleration (PGA) is a measure of earthquake acceleration on the ground and an important input parameter for earthquake engineering. Unlike the Richter magnitude scale, it is not a measure of the total size of the earthquake, but rather how hard the earth shakes in a given geographic area.

Unlike the Mercalli intensity scale, it is measured by instruments, not from personal reports, although it generally correlates well with the Mercalli scale.

Peak ground acceleration can be expressed in g (the acceleration due to Earth's gravity) or in m/s2 (1g=9.81 m/s2).

The peak horizontal acceleration (PHA) is the most commonly used type of ground acceleration in engineering applications.

Other ground motion parameters used to characterize earthquake motion include peak velocity and peak displacement.
PGA         Mag         Depth         Earthquake
2.2g         6.3         5km         2011 Christchurch earthquake
1.7g         6.7         19km         1994 California earthquake
1.26g         7.1         10km         2010 Canterbury earthquake
0.8g         6.8         16km         1995 Kobe earthquake
0.5g         7.0         13km         2010 Haiti earthquake

花小

看了晕~~~~~

A_Wei

太震撼了这次。

songinator

这次的地标加速度市中心是0.78g，但是设计规范是0.22g，9月份的是0.26到0.28之间，所以破坏已经超过了正常的设计范围了。我知道这么说大家还是觉得很难受，因为没有人愿意看到有人遇难，自己的房子没有了。就想说，因 ...
greentree 发表于 2011-3-1 23:34

Have you got it from GNS monitoring equipment?

NZS1170.5 and bridge manual will have to be reviewed for sure for this fault line.

songinator

http://en.wikipedia.org/wiki/Peak_ground_acceleration

Peak ground acceleration
From Wikipedia, the free encyclopedia

Peak ground acceleration (PGA) is a measure of earthquake acceleration on th ...
mandy0512 发表于 2011-3-3 15:18

this 2.2g is vertical ground acceleration         horizontal is not as high

碟田蘑菇

这专业性太强了吧，四楼写的中文都没看懂，楼上几位还整英文的，这都神马跟神马呀，晕。。。

rosy258

呃……专业技术人士的讨论帖~~~~~~~~~

还想外行滴问一下：9楼整理的数据中，为啥没有08汶川的呢？

songinator

呃……专业技术人士的讨论帖~~~~~~~~~

还想外行滴问一下：9楼整理的数据中，为啥没有08汶川的呢？
rosy258 发表于 2011-3-3 22:56

汶川的ground acceleration 可能没有检测 而且感觉也没有横滨地震大 只是我国房子太差

rosy258

谢谢LS解答~~~~~

还有，Unlike the Richter magnitude scale, it is not a measure of the total size of the earthquake, but rather how hard the earth shakes in a given geographic area.
里氏震级是指整个地震的大小，PGA是指定地理位置地表震动的强度----俺理解的对吗？

那么，哪个指标更能直接反映地震的破坏强度？
为什么通常大家都是以里氏震级衡量其破坏性呢？

songinator

谢谢LS解答~~~~~

还有，Unlike the Richter magnitude scale, it is not a measure of the total size of the earthquake, but rather how hard the earth shakes in a given geographic area.
里氏震级是指整个 ...
rosy258 发表于 2011-3-4 14:31

对的   地震级别只是能量的一个measure  再大的级别 如果是地下100公里 没什么 地表的ground acceleration不一定有多大

这次是浅层地震 5km below 6.3级比上次20公里7.3，ground acceleration 破坏力比较大

另外最新消息 NZ bridge manual里5层以上建筑的共振会开始下降 而这次实地检测5层以上的建筑的共振比5层还大一倍然后才开始下降

building code和bridge manual以及NZS1170.5都得review

大概需要一年时间新建筑才能开始建造

图我到了公司再上

rosy258

谢谢，长学问了

话说俺这样懒了几十年的人，突然变的勤学好问起来，也真是难得~~~~

板车升级中

我们都是历史的见证人

songinator

songinator

black line is what we normally design to according to NZS1170.5 spectra

you can see the peak this time is for buildings higher than 5 storeys

plot

还有两个图表，帮LS的补全

plot

songinator

多谢 中心思想都差不多 我就懒得都发了

plot

这次地震的强度已经在新西兰现行的code之外，所以损失很大。
另外大家关心的CTV大楼，据说是在很早以前设计的，当时的code跟现在的有很大不同。

mingroe

被震晕了后，再看到这样技术的贴子。终于明白为何有那么多的建筑倒了。解了心中的一个疙瘩。也明白了。咱碰到了千载不遇的地震。谢谢。谢谢LZ

nb0580

帮楼主补充下： IPENZ 是 新西兰工程师协会 Institution of Professional Engineers New Zealand

剑客浪心

所以结论是什么                 ？

NZLaoMike

剑客浪心 发表于 2016-5-9 14:16
所以结论是什么                 ？

结论就是：一震可以保500年之内屁事没有。 如果你信他是专家不是砖家的话