SMN

SWrucWural Analysis of HisWorical ConsWrucWions – Jerzy Jasieńko (ed) © 2012 DPNH ProcławH PolandH ISSN 0860-2395H ISBN 978-83-7125-216-7

cfNfTE EiEMENT ANAivpfp lc TeE TAfZelr tATEo pTATflN pfTE fN CefNA man gianwuN, Chun ning O ABpToACT qhe qaizhou tater ptation pite was an ancient masonry structure ruin in ChinaK ft was built in the pouthern pong aynastyI and was recently discoveredK qhe main structure had been severely damagedK fn order to understand its current structural propertiesI and provide a scientific basis for protection designI by using Akpvpqj softwareI nonlinear finite element analysis and parameter analysis were proceededI includingW ENF the crack patternI deformation and stress under four load casesX EOF parameter analysis of backfill bulk densityI modulus on the maximum principal tensile stress and compressive stressK qhe conclusion isW ENF qhe most unfavourable condition to the foundation is the combination of Eweight H backfill pressure H additional loadFX qhe most unfavorable load case to the main structure was Eweight H backfill pressure H water pressure H additional heap loadFX EOF the maximum principal tensile stress of the main structure is very sensitive to the changes in bulk density of the backfillK heywordsW cinite element analysis, Taizhou tater Station Site, Ancient masonry structure NK fNTolarCTflN qhe qaizhou tater ptation was built in the pouthern pong aynasty EAa NNOT JNOT9F of ChinaK ft was halfJunderground masonry structure and its function was to vessel traffic for the pouth date of the ancient qaizhou CityK fts ruin was discovered in OMM9 and was considered to be of great value to study the history of ancient qaizhou CityK ft was approved as a municipal heritage conservation unit in OMNMK qhe length of the qaizhou tater ptation pite is OUKS mI and the width is N4KNR mK ft had been found locally collapse and severely damagedI and there were security risksI as shown in cigure NKfn order to understand the true state of the structure and propertiesI and to provide a scientific basis for protection designI detectionI identification and finite element analysis were carried outK

cigK N mresent view of the qaizhou tater ptation pite N iecturerI Civil bngineering aepartmentI kanjing rniversity of Aeronautics and AstronauticsI kanjingI ChinaI

panjianwu]gmailKcom O iecturerI hey iab of rrban C Architectural eeritage ConservationI jinistry of bducationI poutheast

rniversityI kanjingI ChinaI cqnjN9T9]NSPKcom

SMO

OK aETECTflN ANa faENTfcfCATflN te selected three seriously weathered and fracture positions on the wallI and conducted field test to the bricks and mortar with nonJdestructive testing methods EcigKOFK qhe test results showed that the strength level of the bricks was about jrTKR to jrNMI and the compressive strength of mortar was about MKU jma to NKP jmaK qhe wall integrity of both sides of the gate arch was relatively goodI but the wings of walls had a larger range collapseK qhe appearance of bricks showed a mild form of weatheringI and breakageI local rammed earth emptiedK qhere was a very obvious hole in the east part of wall with the size of about NK9 m highI Nm wide and MK9R m deepK qhere was a very obvious hole in the west part of wall with the size of about MKP m highI MK4 m wide and MKR m deepK cigure O showed present situation about wall holesK

cigK O tall holes cigK P coundation damaged qhe font for the authors’ names Efirst name and last nameF is qimes kew oomanI with a cursive character style and a size of NO ptK qhis paragraph is left aligned and with single line spacingK qhe spacing between the title and the authors’ names is 4U ptK qhe names should be separated by comasI and following each author’s name a superscripted number should flag a footnote where the author’s affiliation and contact information will be placedK PK cEA MlaEi fn order to gain better insight into the hidden security risksI Akpvp software was used to do nonlinear finite element numerical simulation analysis on the main structureI mainly studying stress characteristics and security of the main structure under load case combinations such as backfillI floodingI additional heaped loadI etcK PKNK pimplification and assumptions qhe main structure of the qaizhou tater ptation pite was made of brickI stoneI rammed earth compositeK ft was very complexI serious damagedI poor integrityK po we assumed that the main holes were already been repairedK qhe wall brick was simplified as an isotropic continuous homogeneous materialK deometric dimensions was modeled with practical mapping sizeI and internal dimensions was modeled according to the survey resultsK Because it was similar to biaxial symmetryI we take NL4 part of the whole main structure to establish the cbA modelK PKOK marameter values Considering the test dataI the geological survey report and masonry specificationI in accordance with the principle of partial conservative valueI the parameter values of cbA models were as followsW ENF tall brick densityI elastic modulusI moissonDs ratioI compressive and tensile strengths were OOMM kgLmPI NNNO jmaI MKOI MKU jpa and MKMS jpa respectivelyK EOF Backfill densityI elastic modulusI moissonDs ratioI cohesionI internal friction angle were N9MM kgLmPI OMjmaI MKPRI NM kma and OM degrees respectivelyK EPF rndisturbed soil densityI elastic modulusI moissonDs ratio were N9MM kgLmPI 4M jmaI MKPR respectivelyK E4F tater pressures Eincluding the lateral pressure and buoyancyF were added to the main structure as surface loads directlyK ERF Additional heap load on the backfill was R kmaK

SMP

PKPK Element and meshing Commercial finite element software Akpvpqj Eversion NPKMF was used to establish a solid modelI and then meshed the modelK qhe finite element mesh was shown in cigure 4K qhe element types were plifa4R Emodeling the backfill and undisturbed soilI using the aruckerJmrager constitutive modelF and plifaSR Emodeling the main structureI using the tilliamJtarnke failure criterionI considering cracking and crushingFK qhe element size was MKR mK qhe number of elements was approximately ONMMMK

EaF qhe whole model EbF jain structure EcF backfill EdF undisturbed soil

cigK 4 cbA model ENL4 of the qaizhou tater ptation piteF PK4K Analysis type

PKQKNK Nonlinear analysis konlinear analysis was carried out to study the crack patternI deformationI stress of the main structureI and the stress of foundation under the combined effect of four load casesI includingW ENF teight H backfill pressureK qhis case mainly simulated overburden backfillX EOF weight H backfill pressure H water pressureK qhis case mainly simulated the situation about the combination of adverse conditions after overburden backfill such as the high water levelI backfill drainage due to poor permeability etcKX EPF teight H backfill pressure H additional loadingK qhis case mainly simulated adverse conditions such as loads of outbuildingsI construction of temporary heap load after overburden backfillX E4F teight H backfill pressure H water pressure H additional heap loadK qhis case mainly simulated adverse conditions considering the combined influence of EOF and EPFK

ENF Crack Elateral viewF EOF Crack EPa viewF EPF Crack Epartial viewF

E4F jain pNEmaF ERF jain pPEmaF ESF jain rxEmF ETF Base pPEmaF

cigK R oesult of ioad case koK4 Eweight H backfill pressure H water pressure H additional heap loadF

PKQK2K marameter analysis fn parameter analysisI the main structural material model was set as linear elastic materialI then analysis were carried out to study the impact of such factors as backfill bulk densityI elastic modulus on the principal tensile stress and maximum principal compressive stress of the main structureK

SM4

PKRK Analysis result

PK5KNK Nonlinear analysis result According to the cbA analysis result of the four load casesI the most unfavorable load case to the foundation was Eweight H backfill pressure H additional heap loadFK ft caused that base pressure was slightly larger than the bearing capacity of foundationK qhe base pressures caused by the other three load cases were less than the bearing capacity of foundationI but the surpluses were insufficientK qhe most unfavorable load case to the main structure was Eweight H backfill pressure H water pressure H additional heap loadFK ft caused that some cracks occurred at the end part of the wallI as shown in cigure RK fn all load casesI the main structure did not appear crushing areaI the principal compressive stress had a large amount of surplusK qhe lateral displacement of the main structure was also smallerI namelyI the main structure had a high overall stabilityK PK5K2K marameter analysis result qhe relationship between the maximum first principal stress Edefined as pNjaxF I the maximum third principal stress Edefined as pPjaxF and backfill densityI elastic modulus were shown in cigure SK

ENF pNmaxI pPjax vsK backfill density EOF pNmaxI pPjax vsK backfill elastic modulus

cigK S marameter analysis result

pNjax and backfill bulk density showed a nearly linear growth relationship Ecigure S ENFFK then the bulk density was increased from N4 kkLmP to N9 kkLmPI pNjax was increased by SOBKft showed that pNjax was very sensitive to the changes in backfill bulk densityK pPjax and backfill bulk density showed a nonJlinear growth Ecigure S EOFFK then the bulk density was between N4 kkLmP and NT kkLmPI small changes occurred in pPjaxK then the bulk density was increased from NT kkLmP to N9 kkLmPI pPjax was increased by N4BK pNjax and backfill elastic modulus showed a nonlinear reduction relationship Ecigure S EOFFK pNjax was decreased PNB when the elastic modulus was increased from R jma to PM jmaK pPjax and backfill elastic modulus showed a nonlinear reduction relationship too Ecigure S EOFFK then the elastic modulus was increased from R jma to PM jmaI pPjax was decreased by OPBK qhereforeI pNjax and pPjax were quite sensitive to the changes in elastic modulus of the backfillK 4K ClNCirpflNp Based on the above site testing and cbA analysis resultsI the following conclusions and recommendations could be presentedW

NF bffective measures should be taken to strengthen the ground and improve the bearing capacity of the foundationK

OF perious damage in the main structure of the qaizhou tater ptation site such as cracks or holes should be repaired with methods such as groutingK

PF After repairI the waterproof layer and drainage system should be prepared carefullyK oeliable measures should be taken to reduce the earth pressure on the crackJprone partsK qhe backfill should have good permeability and its bulk density should be smallK

4F Additional load should be avoid delivering directly to the main structureI if unavoidableI lightweight materials should be selectedI and technical measures should be taken to make the load

- M. 1

M

M. 1

M. 2

M. 3

M. 4

M. 5

M. S

M. 7

14 15 1S 17 18 19

densityEkkLmPF

fncr

ease

d o

ange

S1MaxS3Max

- M. 35

- M. 3

- M. 25

- M. 2

- M. 15

- M. 1

- M. M5

M5 1M 15 2M 25 3M

elastic modulusEjmaF

fncr

ease

d o

ange

S1MaxS3Max

SMR

evenly delivered to the original main structureI to avoid severe local uneven loadK qhe construction load should be strictly controlled in the repair and strengthening constructionK

RF A regular inspection system should be establishedI and the longJterm deformation and subsidence of the main structure should be monitoredK

AChNltiEadEMENTp qhis paper was supported by the kational katural pcience coundation of China Edrant koK RNNMUOPUFK oEcEoENCEp xNz Ansys China itdK EOMMTF Ansys konlinear Analysis duide Ein ChineseFK BeijingI moCK xOz whang tdI ui uaK EOMM9F ptability analysis of the ancient wall of mingyao city Ein ChineseFK

Building structure P9EPFW NNMJNNOK xPz iei edI iu gdI tu qKEOMMTF ptrengthening of the ancient wall of mingyao city Ein ChineseFK

Building structure PT EpNFW OP4JOPTK x4z vang jK EOMNMF oepair and ptrengthening of the ancient wall of kanjing city Ein ChineseFK

Building structure 4M EpNFW O9NJO94K xRz Chen iiI Cao pvK EOMMTF rsing drouting method to strengthen tuchao date of kanjing

Ein ChineseFK Building structure PTEpNFW ORUJOSMK xSz iiang qK EOMMUF mrotection and strengthening of the kiya site in uinjiang Ein ChineseFK aunhuang

oesearch ESFW P4JPUK xTz aeng CvK EOMM4F pafety analysis of the brick arch structure Ein ChineseFK poutheast rniversityK

jaster qhesisK xUz ging aeI whao daI ju BdI Cao pvK EOMM9F pafety analysis of phangfang qumulus in kanjingEin

ChineseFK special structure OSEOFW TNJT4K