百科知識視頻之煎蛋小學堂47 頭朝下的車為何這么屌？

On June 7,1692,the Jamaican city of Port Royal,a notorious pirate haven,sank into its own harbor.This disaster (or blessing,depending on who you ask)was caused by liquefaction of the ground following a major earthquake,and we know it happened at exactly 11:43 am thanks to a pocket watch that went down along with two thirds of the town and over 2000 people.

1962年6月7日 牙買加海盜天堂 皇家港口，在自己的港口沉沒了。這場災難 或說是福祉(這取決于你說的對象)在地震之后的地面液化造成的，我們知道事件發(fā)生在上午11時43分 一只懷表停在了此刻 還有三分之二的小鎮(zhèn)沉沒 2000余人失蹤。

Liquefaction happens when waterlogged,loose soil,we call it "sand",turns into quicksand temporarily.If you look closely at land,you'll realize that it's actually comprised of tons of tiny rocks,and their roundness and roughly uniform size,mean that there's space between that can get filled by water.When we step on saturated sand at the water's edge,it's fairly stable because the particles get pushed together and rest on each other,while any excess water escapes by flowing away to where the pressure is lower.

液化發(fā)生在浸滿水的松散土壤 我們稱之為沙地 暫時變成流沙時。如果你仔細觀察沙地 會發(fā)現它其實是由無數的小石塊組成的，它們圓形的形狀和幾乎一致的大小 意味著其間的間歇可以被水填入。當我們踩在水邊的濕沙上時，沙地仍很穩(wěn)定 這是因為沙粒被擠壓在一起 相互抵觸，而多余的水則流到壓力較低的地方。

We can(and do)build buildings on wet sandy soil,since the weight of the grains,and the friction between them makes the soil behave as a solid most of the time,But in an earthquake,soil particles repeatedly jostle back and forth so much that the water can't flow away.Loosely packed dry soils tend to compress under stress,but with incompressible water unable to escape the gaps between grains,the soil can't compress and the water takes the load.

我們的確能在濕沙質土上蓋房子 因為沙粒的質量 以及相互間的摩擦力讓濕土在多數時候呈現出固體特征。而地震時 土壤顆粒不停地來回碰撞 水無法流走。松散的干沙在壓力下會被壓縮 而當難以壓縮的水 無法從沙粒間隙間流走時，土壤就無法被壓縮 水占了上風。

Unfortunately,water,as a liquid,doesn't have much structural integrity,so if the saturated soil is forced to compress too much too quickly,it will start to act like a liquid,and dense objects resting on the now liquefied soil will risk.You can experience liquefaction for yourself in the water-soaked sand near the edge of a beach,It feels pretty soild if you stand still.but if you wiggle your feet,the movement causes the sand to liquefy beneath you,and you start sinking.

不幸的是 水作為一種液體 其結構完整性很差 因此如果濕土在過短時間內被過度擠壓。它就會表現出液體性質，坐落于已液化土壤之上建筑就會沉下去。你可以在海灘邊浸滿水的濕沙上體驗下液化的感覺 你站著不動時 感覺它像固體。但當你晃腳時，這動作會使你腳下的沙子液化 你便開始下沉。

On a larger scale,earthquake-induced liquefaction can swallow cars,roads,and even enormous apartment complexes.In other words,earthquakes can create quicksand,except that when the shaking stops and the soil particles are no longer suspended in water,the ground solidifies again and anything that sank becomes stuck,Which is what happened to this carrrr......

大范圍而言 地震引起的土壤液化會吞沒 汽車 道路 甚至是大房子。換句話說 地震會產生流沙，除了地震停止 沙粒不再懸浮在水中，地面再度固化 任何沉下去的東西都會被卡住。這就是為何這輛車這么吊....