 Mae cyfnodd yn cael perffodus gwahanol nawr, mae'r cefnodd yn cael perffodus gwahanol sy'n gwahanol. Mae ei chylau gwahanol yn cael perffodus gwahanol a'i rhai chyrsiau. What that means in terms of this consolidation test? If we have our log SIGNA prime axis of the x axis and avoid rhaethu on the y axis... felly mae'n amlwg Rabb, mae'n roi'r rhaglen a gynrych yn y rhan o'r rhaeon gael ddechrau'r rhaglen, i ddydd y rhaglen yn cyrraed o gysig dros rhai gwahanol. Ac mae'n credu rhai gwahanol, oherwydd mae'n gweld unig lle i ni'n cychwyn neu wrth gwrs dyngen nhw, mae'n cael eu reimhalygiad rhai gwahanol. Y tyd wedi gyrraethau'n gynnig am yma, We've removed the load increment so we are in this position and we removed the load increment so we travel backwards on the x axis. The soil would go through something like this where there's some rebound, so it's not fully plastic material, but it's not fully elastic. felly mae'n rhaid i'r ddweud yn cael ei ddweud, ond mae'n rhaid i'r ddweud yn cael ei ddweud. Ond, i'r ddweud, ydym yn ei ddweud yna, y gwanaf am y cyflosedd. Alla y gwybod, mae'n ddweud yn ganunio fel arall. Felly, y gwanaf ar y cyflosedd yn cael ei ddweud. Mae'n gwybod ar y pwylltau a chyflosedd yn gwybod cyflosedd o'i rhai ddweud, ac mae'n ddweud yn cael ei ddweud. Felly yw'r fnutrwyd yn ychydigol i'w testa, yna'r gyfer hysroesol yng nghymru. Felly, when we are thinking about consolidation, it's important to know whether something is normally consolidated, which means that it's on the normal compression line, or it's over-consolidated, which means that it's previously experienced stresses that are greater than what it's currently experiencing, That's why the stress history is important for a soil. A soil that exists on the normal compression line is called normally consolidated. And a soil that exists within the hysteresis loop is called overconsolidated. Now this is important because you can see that if we have a soil that on the normal compression line is normally consolidated we apply stress to it. Mae'r rhesiwn gwneud llunio gwmp, ac mae'r cefnodiidd yn wych yn y gw cooperationnau. Dyma'r llunio cymryd o'r rhesiwn gwneud yn ffordd, ac felly mae'nbikeig cywc mewn ni fod yn angen i'r llunio cymryd, bod yw'r hynny o'r llunio cymryd yw o'u rhoi, ac mae'n imbwysig o'r llunio cymryd yn cymryd. a tych yn gwneud y cyd-degwydd yma, yn y cyd-degwyd, y cyd-degwydd yn gallu hystureeysu. Mae gennym iawn o'u cyd-degwydd cyd-degwydd gyda gofod o'r cyd-degwyddau. Mae'r cyd-degwydd yn cael ei ddifasol a'r cyd-degwydd yn cael ei ddifasol a'r cyd-degwydd yn cael ei ddifasol. Ac ydych yn cyd-degwyddau'n yn cael ei ddifasol er mwyn i siaradau, y gynnwys ystod o ran y llangol, er gollwch o bwysau ddeunedol wedi gyd i'r fethau cael eu bod hefyd yn gwneud y gyrddwyr cynyddiad. Felly yw wnaeth digwydd yng nghyntfarniau maethmantecol efallai oho gyda rom yn roedd y rhoi cofnidol, o dddw i'r o子ol, ac mae hynny lefyn o'r dod eich grafwstwyth ddefnyddol i'r hollwch ei hwn yn hollwch ei bodion at deunydd For soils on the normal compression line, the previous maximum stress is the same as their current stress, so they haven't had anything greater than what they're currently experiencing. So for normally consolidated soils, the over consolidation ratio is equal to 1. For soils that are over consolidated, you can see that the previous maximum stress is greater than their current stress. So for over consolidated soils, you have an OCR that's greater than one. So we know how to calculate the current stress in a soil, and I've shown you how to do that in one of the previous videos. But how do we determine the maximum previous stress? Well, we can do that from a one-dimensional odometer test by analysing the results during loading. And I'll show you how to do that now. I'll just create some space here. So to calculate the maximum previous stress that all over consolidated soil has experienced, we take the results of the odometer test where we have a long effective stress on the x-axis and the void ratio on the y-axis. And all over consolidated soil sample will exhibit a change in void ratio that looks something like this, where it has an initial void ratio, and then it decreases. So this is the second part of the hysteresis loop. So it essentially rejoins the normal compression line somewhere around here. So if we take the gradient of this normal compression line and take it backwards, it might look something like this. So this is our normal compression line. Okay, the next step is to identify the point of maximum curvature on this line. So it's somewhere around here. You can do that more accurately using a computer and looking for the changes in gradient. Okay, so we have identified the point of maximum curvature. The next step is to draw a horizontal line from that point of maximum curvature. And then if we take the tangent at the point of maximum curvature, so this is the tangent of the curve, the previous maximum stress is the intersection or the bisection between these two lines, the horizontal line and the tangent. So if we bisect these two points in the middle, so if we draw a line that cuts this little triangle in half and it looks something like this. So we've cut this triangle in half, we've halfed this distance here. This is the point of the maximum previous stress. So if we take the valley down and read it from the x-axis, this here is the max previous effective stress.