Quicksand: Yam dab tsi tshwm sim?

2024 Tus sau: Henry Conors | [email protected]. Kawg hloov kho: 2024-02-12 07:49

Taug kev ntawm qhov chaw hauv qhov xwm txheej, txaus siab rau qhov ntxim nyiam ntawm cov paj ntoo, mloog cov noog xuav cov nkauj zoo siab, koj tuaj yeem yuam kev hauv cov xuab zeb nrawm. Tab sis koj yuav tsum tau ceeb toom tam sim ntawd tias txhua yam tsis txaus ntshai, raws li pom nyob rau hauv qee cov yeeb yaj kiab ntawm "kev ntshai heev" hom. Yog lawm, tau kawg, nws yog qhov zoo dua los zam lawv, tab sis tib lub sijhawm, koj yuav tsum tsis txhob ntshai. Muaj ob peb txoj cai sib xws, kev paub uas yuav pab kom tsis txhob muaj xwm txheej zoo li no.

Dab tsi yog qhov nrawm nrawm? Qhov no yog ib qho kev nthuav dav tiag tiag, tab sis tsis yog hom av peculiar. Ib qho kev sib xyaw uas muaj cov khoom zoo-grained, av nplaum thiab dej (hauv thaj chaw suab puam - sib tov ntawm xuab zeb thiab huab cua). Nws zoo nkaus li khov, tab sis yuav tsis ruaj khov thaum lub siab siv rau nws qhov chaw. Nws yog tsim thaum dej oversaturates xws av. Zoo tib yam, ib txwm tshwm sim xuab zeb (chaw txua txiag zeb, lub roob, hiav txwv) muaj cov nplej ntawm cov nplej ntawm cov nplej uas muaj dej lossis huab cua). Txij li ntau cov xuab zeb nplej yog elongated,lawv cov kev sib cais, thiab tom qab ntawd cov voids yuav yog los ntawm 30 mus rau 70 feem pua ntawm cov huab hwm coj. Cov txheej txheem no zoo ib yam li lub tsev ntawm daim npav thaum qhov chaw nruab nrab ntawm daim npav loj dua qhov chaw lawv nyob. Cov kua ua rau tsim cov av liquefied, uas tsis tuaj yeem tiv taus qhov hnyav.

Quicksand tuaj yeem ua rau sawv ntsug thiab cov dej ntws ntws mus rau sab saud (xws li cov dej ntws hauv artesian). Cov dav hlau dej coj mus rau pem hauv ntej tiv thaiv lub ntiajteb txawj nqus thiab ua kom cov av ua kom qeeb. Saturated sediments yuav zoo heev, tab sis me ntsis mechanical stress on lawv nto pib liquefaction. Qhov no ua rau cov xuab zeb tsim rau hauv slurry thiab poob zog. Cov dej cushioned tsim cov xuab zeb sai, liquefied sediments, thiab spongy, kua zoo li av zoo nkauj. Cov khoom nkag mus rau hauv ib puag ncig xws li dab dej mus rau theem uas lawv qhov hnyav yog sib npaug ntawm qhov hnyav ntawm qhov sib tov (los ntawm av thiab dej). Liquefaction yog ib qho tshwj xeeb ntawm qhov tshwm sim nyob rau hauv kev xav. Yog li, thaum muaj av qeeg, qhov pore siab hauv cov dej hauv av ntiav sai sai. Cov av ntub dej poob nws lub zog, uas ua rau lub cev qhuav dej thiab lwm yam khoom nyob ntawm nws qhov chaw.

Quicksands tsim qhov chaw uas muaj dej ntws zoo, hauv qhov chaw marshy lossis ntub dej, ze cov dej ntws, ntawm ntug hiav txwv, txawm hais tias lawv feem ntau tsis yooj yim txheeb xyuas. Yog hais tias koj dheev nkag mus rau hauv lawv, ces lawv rov qab sai thiab maj mam, reacting nrog ib ncua ntawm ob peb vib nas this. Lawv yogyog cov kua dej uas tsis yog-Newtonian, uas yog, thaum so lawv yog cov khoom (gel-zoo li daim ntawv), tab sis qhov cuam tshuam me ntsis rau lawv ua rau muaj qhov viscosity tsawg. Nyob rau hauv cov suab puam, lawv kuj pom, tab sis tsis tshua muaj heev, qhov chaw ntawm cov xuab zeb tshwm sim, piv txwv li, nyob rau sab lee ntawm dunes. Tab sis qhov poob qis yog txwv rau ob peb centimeters, vim hais tias ib zaug huab cua hauv qhov khoob ntawm cov xuab zeb tau raug tshem tawm (thiab qhov no tshwm sim sai), lawv rov ua dua.