Anchorage Depth of Rail Spikes thiab Critical Threshold Design of Sleeper Concrete Bond Force
Yuav ua li cas kom muaj nuj nqis kev sib raug zoo ntawm spike anchorage qhov tob thiab pob zeb ua vaj tse zog?
Lawv ua raws azoo zog muaj nuj nqi kev sib raug zoo: hauv qab ntawm qhov tseem ceeb, daim ntawv cog lus muaj zog nce exponentially nrog qhov tob; dhau qhov pib, kev loj hlob qeeb qeeb thiab toj siab. Piv txwv li, qhov tob qhov tseem ceeb rau cov resin{1}}anchored spikes yog 150mm: nce qhov tob ntawm 100mm mus rau 150mm boosts bond zog los ntawm 200%, thaum nce ntawm 150mm mus rau 200mm tsuas yog ntxiv 15%. Qhov kev sib raug zoo no yog lub hauv paus tseem ceeb rau kev tsim kho qhov tob.
Vim li cas qhov tseem ceeb anchorage qhov tob sib txawv ntawm hom pw tsaug zog?
Qhov sib txawv stems los ntawm cov pob zeb ua kom muaj zog thiab kev txhawb zog sab hauv. Ordinary qhob pw tsaug zog (C50, ntom ntom) muaj qhov tob ntawm 140mm-150mm. Prestressed concrete sleepers (C60, high-density concrete with prestressed strands) have stronger bond strength, so the critical depth drops to 120mm-130mm. Ntoo sleepers lossis pob zeb sib txuas nrog cov xov xwm anchoring sib txawv yuav tsum tau rov xam qhov tob tob-txheej txheem qhob pw tsaug zog qhov tseem ceeb tsis tuaj yeem siv ncaj qha.
Yuav ua li cas anchorage tsis ua hauj lwm hom tshwm sim nrog tsis txaus anchorage qhov tob?
Qhov feem ntau tsis ua hauj lwm yogspike rub- tawm, muab faib ua "static rub- tawm" thiab "dynamic rub- tawm." Static rub- tawm tshwm sim nrog hnyav nyob rau hauv - qhov tob anchorage: spikes yog ncaj qha rub tawm los ntawm kev tsheb ciav hlau longitudinal rog. Dynamic rub- tawm ntau dua: rov ua dua lub tsheb ciav hlau kev co maj mam txo qis zog; thaum nws tsis tuaj yeem tiv taus cov khoom hnyav ntxiv lawm, spikes loosen zuj zus thiab nws thiaj li rub tawm. Ob qho kev ua tsis tiav ua rau txoj kev tsheb ciav hlau poob, ua rau muaj kev sib tsoo hnyav.
Dab tsi cuam tshuam tsis zoo rau qhov tob anchorage ntau dhau rau cov neeg pw tsaug zog thiab kev pab cuam lub neej?
Excessive depth (e.g., >200mm) ua ntejua rau pw tsaug zog sab hauv: spikes yuav nkag mus rau prestressed strand tiv thaiv khaubncaws sab nraud povtseg los yog txawm txiav strands, ua rau pw tsaug zog tawg thiab lub zog poob. Qhov thib ob, cov ntu ntev dhau los ua kom pom tseeb ntawm cov pob zeb shrinkage kev ntxhov siab ntawm lub hauv paus loj, ua rau khoov deformation. Tsis tas li ntawd, qhov tob tob ua rau muaj kev tsim kho nyuaj, ua rau lub sijhawm ntev ntawm tus neeg sawv cev kho kom zoo, txo kev ua haujlwm, thiab tsis muaj cov txiaj ntsig tseem ceeb ntawm lub zog.
Yuav ua li cas kom tswj tau qhov tob ntawm qhov tob hauv qhov chaw ntawm -kev tsim kho kom tsis txhob muaj qhov sib txawv?
Qhov ntsuas tseem ceeb siv ib qhoanchorage depth locator-ib lub tsho uas muaj siab tshaj lub tsho ntev, nrog qhov ntev sib npaug ntawm qhov tsim qhov tob. Thaum lub sij hawm installation, ib qho kawg ntawm lub locator abuts lub sleeper nto, kom ntseeg tau tias lub embedded ntev phim lub locator ntev. Rau resin anchoring, aquantitative txhaj tshuajtswj tus neeg sawv cev ntim, tiv thaiv ntab (tus neeg sawv cev tshaj) lossis tsis txaus (tus neeg saib xyuas tsis txaus). Post-kev tsim kho, random sampling siv lub ntsuas qhov tob los ntsuas qhov ntev ntawm qhov ntev; anchorage qhov tob yog xam los ntawm kev pw tsaug zog tag nrho cov thickness kom paub tseeb tias ua raws.