Study On Structural Properties Of Traditional Dwellings Timber Frame Architecture

Traditional timber frame construction refers to a kind of building which thewooden frame as the main load-bearing structure, while the soil or brick walls as theexternal envelope and separate structure. This type of construction is a majorstructure of ancient Chinese architecture, which has such advantages as a long historyand unique system, its material has good property and is easy to be obtained, variousin form, convenience to machine, economic price and so on. This fits into the Chinesetraditional farming culture, self-sufficiency of ideologyand and life-style, what makethem in our country has extensive application in traditional residential buildings. Theunique architectural style and design approach of timber-frame buildings also reflectthe wisdom of the Chinese nation, which are the important components of China’slong cultural heritage.Traditional timber frame constructions have many advantages, but most of thebuildings are older, the durability of building materials has greatly attenuation underthe environment of erosion of long-term. Farther more, most of the traditionaldwellings were built by local craftsmen with experience, there was no completedesign drawings and supervision of relevant units for quality and safety, the structureitself exists unreasonable place, what cause the damage of the existing traditionaldwellings in different degree. At present，with the rapid development of the newrural construction, new materials and new technologies have been introduced, thequality of people’s life has been improved constantly, people give up old houses andmove to the new one, that makes a lot of traditional residence in a state of neglect orconstant destruction. Therfore the protection of them is imminent.In order to guide the protection and renovation of the traditional dwellings interms of structural safety, and inherit the the construction technology of local culturalrelic buildings, the field investigation and maintenance design for Qin’s old dwelling,which is a typical ancient dwelling in central Henan Province was proceed by ourgroup.The research is based on the support of the "Twelfth five-year" national science and technology support project national, and the principal of XingYangShicultural relic protection center of henan province. The hall of Qin’s old dwelling wasselected as the research object in the paper, the theoretical analysis of structurecharacteristics and finite element numerical simulation was proceed, the deformationlaw and stress characteristics was obtained under various conditions.The paperdiscussed the structure performance and found the weak parts of the structure, andsimple repair method was proposed.The specific research work are as follows:(1) Through the ways of surveying and mapping, interviews and take pictures forthe Qin’s old dwelling on-the-spot investigation, the complete statistics of the housewere obtained. According to the structure characteristics of timber frame system ofQin’s old dwelling hall, this paper expounds in detail form the aspects such asstructure form, construction practice and the damage situation, and does simpletheoretical analysis from the angle of mechanics, discusses its scientific nature andrationality.(2) According to the measured data of the Qin’s old dwelling, three-dimensionalfinite element model is established by using of beam elements and semi-rigid units.Static analysis of the structure is proceed under the action of gravity and snow load.The analysis indicates that the roof is easy to occur slanting, the purlins, Jin Zhu andseven-frame beam are the key mechanical components, the locations about thebeam-column joints, the middle span of the purlins, the connection locations ofpurlines and beam-frames, the mortise-tenon joints of purlines are the weak positions,easy to cause splitting, bending down, tenon pulling from mortise, rolling and so on,these damages directly affect the structure of the safety and reliability.(3) With the purpose of getting the natural vibration characteristics and dynamicparameters for the hall wooden frame, in this paper, the modal analysis of thestructure is carried out. The results pointed out that the first natural vibration periodof the mode is2.1127s, which reflecting the long cycle characteristics of timberframe construction; longitudinal stiffness is weaker than lateral stiffness, it should bestrengthened.(4) Contrast models are established in the paper in order to discusse theinfluence of joint stiffness and roof stiffness for the vibration modes of structure. The results show that the the joint stiffness has significant effects on the structurevibration modes, especially for the first order vibration mode, strengthening themortise and tenon joint connection between the purlins has obvious effect on thelongitudinal stiffness; Changing the roof stiffness has little impact on structural modalbecause of the hall roofing itself larger stiffness.(5) In order to study the seismic resistance of timber frame, time-procedureanalysis is carried out in this article with fully transient analysis method.The resultsconcluded that the displacement of frame is larger under severe earthquake, the peakdisplacement of the beams increase with the increase of height. The raising-of-trussmethod of eaves step is higher than the general practice, what causes the interstoreydisplacement between the baotou beam and seven-frame beam larger, the area proneto occur tenon phenomenon.(6) The acceleration response of the beam layers under severe earthquake showsthat the peak acceleration has a tendency to decrease along with the increase of beamslayer height; The dynamic magnification coefficient between each frame layers isaround1, the connection joints between mortise and tenon have the effect of dampingenergy consumption, and the jionts in the7-purlin beam layer have the mostsignificant effect of energy dissipation.