“凑合”的妙用——基于木建构的利川永顺桥适宜性研究

利川永顺桥是鄂西南地区现存唯一一座木伸臂梁与八字形撑架组合式木拱廊桥,是当地匠人在面对大跨挑战且已有技术、经验不足的情况下,“凑合”了几种既有结构技术实现的一次创新。通过介绍永顺桥的基本情况,分析其产生的背景,并从木建构的角度解析匠人们在面对材料、结构、建造施工等问题时所采用的构造方法,以此分析永顺桥的适宜性,以期对永顺桥的维修保护及价值开发有一定的启发。

木之建构——关于国际当代木构建筑的发展

当今国际木构建筑的新发展要求我们对世界木建构文化重新认识。事实上,木材作为建材的许多优点我们并没有认识清楚。国际上,尤其是欧洲当代木构建筑的新发展正是以这种思想为基础的。欧洲的木构建筑传统实际上也是很深厚的,并且分布很广。经过社会和理论上的准备,一些具有先进意识的建筑大师们成功地探索了当代木构建筑的发展,主要集中在欧洲的阿尔卑斯山地区和北欧地区。我们在接受潮流影响的同时,有必要理解木建构文化在人类不同文明历史发展阶段的意义,尤其是在现阶段作为后工业文明阶段的木建构文化的特性,以及该建筑潮流的建造规律和造型表现力。

湖南历史类木构建筑的节能改造关键技术研究

从分析木材在建筑运用中的优点入手,探讨了木构建筑在节能领域的广阔前景,并针对国内现状分析了推广木构建筑困难重重的原因,提出以历史类木构建筑的节能改造作为研究对象的必要性以及重要意义。并结合目前国内普通建筑的节能措施,对可以运用于湖南地区历史类木构建筑的节能措施进行研究,提出可行的建议。

木结构建筑防火技术研究及应用

木结构建筑在中国拥有非常悠久的历史,并广泛应用在社会生活中的各个方面。木结构建筑之所以受到人们的喜爱,是因为它与其他类型的建筑材料相比更加舒适和便利,然而木建构建筑虽然有其优势,但是它在人类生活中引起火灾的隐患也比较突出。本文对木结构建筑进行了详细的分析,主要阐述了不同类型的木质结构的防火机理,旨在根据木质结构的类型不同,制定相应的防火措施,从而最大程度的降低木结构建筑在火灾中的损失。

Mechanical properties of monodirectional Gutou mortise-tenon joints of the traditional timber buildings in the Yangtze River region

The mechanical properties of the monodirectional Gutou mortise-tenon joints of the ancient Chinese traditional timber buildings in the Yangtze River region were studied using the experimental method. Three monodirectional Gutou mortise-tenon joints were designed according to the actual configurations. The failure modes,the hysteretic curves,the skeleton curves, the rotation rigidities, and the energy dissipation capacity of this type of mortise-tenon joints under the low cyclic reversed loading were obtained. The results show that the hysteretic curves of the monodirectional Gutou mortise-tenon joints appear to be Z shape and have obvious pinch effects. During the process of the test,these mortisetenon joints pass orderly through the elastic stage,the yield stage and the failure stage. The energy dissipation capacity of these mortise-tenon joints generally decreases with the increase in the rotation angle. The equivalent viscous damping coefficients of the monodirectional Gutou mortise-tenon joints are between 0. 161 and 0. 193. The results can provide the theoretical base for the computing analysis and repair design of Chinese traditional timber buildings in the Yangtze River region.

Experimental study on aseismic behaviors of Chinese ancient tenon-mortise joint strengthened by CFRP

In order to well protect Chinese ancient buildings, aseismic behaviors of Chinese ancient tenon-mortise joints strengthened by carbon fibre reinforced plastic （CFRP） are studied by experiments. Based on the actual size of an ancient building, a wooden frame model with a scale of 1 ： 8 of the prototype structure is built considering the swallow-tail type of tenon-mortise connections. Low cyclic reversed loading tests are carried out including three groups of unstrengthened structures and two groups of structures strengthened with CFRP. Based on experimental data, moment-rotation angle hysteretic curves and skeleton curves for each joint are obtained. The energy dissipation capability, stiffness degradation and deformation performance of the joints before and after being strengthened are also analyzed. Results show that after being strengthened with CFRP, the tenon value pulled out of the mortise is reduced; the bending strength and the energy dissipation capabilities of the joint are enhanced; stiffness degradation of the joint is not obvious; and the deformation performance of the joint remains good. Thus, the CFRP has good effects on strengthening the tenon-mortise joints of Chinese ancient buildings.

Structural Carpentry in Qing Dynasty-A Framework for the Hierarchically Modularized Chinese Timber Structural Design

This article, by using mathematical expressions, offers a scientific framework for understanding how the grading system of Qing′s structural carpentry determines the design and construction in the grand style timber architecture.The Qing′s grand style timber structure, which is ready for prefabrication and assembly, is extremely hierarchical oriented and significantly standardized. The general procedure in designing a grand style timber structure is to start with the grade that defines the basic module (dou kou); next comes with the number of bracket set (cuan), the number of longitudinal bays and the number of purlins which affect its plan and cross section; thirdly choose a roof type that determines its longitudinal section and the facade as well. A series of formulae are conducted to help depict the layout, cross sectional roof curvature and special longitudinal treatments in 4 sloped and 9 spined roofs respectively.

Research and development of seismic base isolation technique for civil engineering structures

Base isolation is one of the most promising alternatives among the structure control methods. In recent decades, base isolation has been seriously considered for civil structures, such as buildings and bridges, subjected to ground motion. The research achievements and development of seismic base isolation technique for civil structures in Huazhong University of Science and Technology (HUST) are introduced. The achievements include project applications, experimental research results and theoretical innovation.

Historical Timber-Framed Buildings： Typology and Knowledge

This paperprovides a historical overview intending to clarify the methods of interpretation of timber-framed buildings by different authors of construction treatises, and structural intentions of the carpentry designers and master builders, throughout the centuries, until the period when it became scientific structural theory. It describes the ＂box-frame＂ construction that appeared in Lisbon, after the earthquake of 1755, characterized by its good seismic resistance. This knowledge is important to determine a strategy of an efficient restoration practice in historical constructions which require an intervention subordinated to its raised patrimonial and artistic value, minimum, which respects the authenticity of its structural and construction conception and which is reversible and compatible, in physical, chemical, mechanic and aesthetic terms. Empirical understanding of the most important properties of wood to structure purposes, the defects of structural timbers, the framing and the preliminary survey followed by the structural survey were some of the difficulties which can be overcame in practice.

Dynamic Analysis of Structural Columns Subjected to Impulsive Loading

For a building structure subjected to impulsive loading, particularly shock and impact loading , the response of the critical columns is crucial to the behaviour of the entire system during and after the blast loading phase. Therefore, an appropriate evaluation of the column response and damage under short-duration impulsive loading is important in a comprehensive assessment of the performance of a building system. This paper reports a dynamic analysis approach for the response of RC columns subjected to impulsive loading. Considering that the dynamic response of a column in a frame structure can also be affected by the floor movement which relates to the global vibration of the frame system, a generic column-mass model is used, in which a concentrated mass is attached to the column top to simulate the effect of a global vibration. To take into account the high shear effect under impulsive load, the model is formulated using Timoshenko beam theory, and three main nonlinear mechanisms are considered. Two typical scenarios, one under a direct air blast loading, and another under a blast-induced ground excitation, are analyzed and the primary response features are highlighted.

The Moisturein Capillaries of Building Materials

The behavior of building materials in constructions of civil structures is influenced by the surrounding moisture and it is a crucial for intensively examined field of the construction physics. Most standard building materials are characterized by a porous structure, which results in the ability to receive water in a liquid as well as gaseous form in the inner pores. The water fills the storage space of pores under certain conditions; it is transported and transferred back to the surroundings. Many technical studies show that the moisture monitoring is prevailingly based on experiments. Previous calculating methods introduced, e.g., by Glaser, which became the basis for the standard calculations in many European countries in the 1960s, are not always sufficient with respect to the demands of the civil structures. The moisture influences thermo-insulating properties of the material. By a change of the thermo insulation properties of the construction also the thermal and diffusion scheme of the construction is changed and its thermal resistance is decreasing. Faults in the thermo-technical projects occur when thermal conductivity coefficient L values for material in a dry state are substituted.The aim of the research is to determine the capillary conductivity coefficient as a characteristic material moisture parameter of the building materials by the means of a non-destructive method using the experimentally assembled apparatus developed at the Department of Civil Engineering, Brno University of Technology. Keywords： Capillary conductivity coefficient, moisture transfer, EMWR （electromagnetic microwave radiation）, diffusion

Experimental study on seismic characteristics of typical mortisetenon joints of Chinese southern traditional timber frame buildings

The seismic characteristics of four typical mortise-tenon joints of Chinese southern traditional timber frame buildings were researched, including Yanwei mortise-tenon joint （including dropping Yanwei mortise-tenon joint）, Shizigutou mortise-tenon joint, Ban mortise-tenon joint and Mantou mortise-tenon joint. Experiments on thirteen specimens were carried out. Failure modes, hysteresis curves, skeleton curves and rotational stiffness were studied. The results provided a theoretical basis for seismic research, protection and maintenance of Chinese southern traditional timber flame buildings.

Current Situation and Future Development of Timber Structural Houses in China

The current situation and opportunities of timber structural houses development in China wereintroduced and analyzed. There is a great potential market of timber structural housing in China. In the meantime, some problems about wooden housing should be paied more attention to and be solved in the future.