| Traditional Tibetan rubble architecture is one of the most ethnic architecture in China.It is widely distributed in the western Tibetan area.There are more than 100 famous traditional buildings in Lhasa alone.Most of them are built by themselves according to experience,with local materials and natural materials such as rubble stone and yellow mud.Due to the defects of natural materials,the mechanical performance and durability of Tibetan rubble masonry will be significantly reduced.Under the influence of natural factors,the wall will gradually tilt,crack,and even damage.Tibetan rubble masonry is mainly subjected to vertical pressure load.What’s more,the basic mechanical properties and mechanical mechanism of masonry are the key to strengthening traditional rubble masonry and evaluating the bearing capacity of existing rubble masonry.The irregularity of stone and the randomness of masonry result in the discreteness of traditional Tibetan rubble stone construction,and the mechanical performance is quite different from that of ordinary regular masonry.In order to protect the traditional Tibetan architectural culture and further study the mechanical properties,it is particularly important to study the basic mechanical properties and mechanical mechanism of traditional Tibetan rubble masonry under compression.Based on this,this paper studies the basic mechanical properties of traditional Tibetan rubble masonry under compression by means of experiment,theory and numerical simulation.(1)Through a series of compression tests of Tibetan rubble masonry,the failure modes of the whole specimen and the failure characteristics of the internal single stone are obtained,and four typical stages of the whole process of Tibetan rubble masonry under compression are given.The failure mechanism of Tibetan rubble masonry under compression is revealed by analyzing the whole process of specimen under compression.The mechanical parameters such as compressive strength and elastic modulus of Tibetan rubble masonry are compared and analyzed.The correlation between the basic mechanical parameters of Tibetan rubble masonry is established systematically.(2)Based on the experimental data,the dimensionless stress-strain curve of Tibetan rubble masonry is given.The uniaxial compression constitutive model of Tibetan rubble masonry is established by using two-stage regression analysis method and damage theory combined with statistical analysis method.A unified compression constitutive model with definite parameters of physical meaning is obtained.(3)The two-dimensional model of Tibetan rubble prism was numerically analyzed by using discrete element particle flow.The stress distribution and stress mechanism of Tibetan rubble prism during compression are studied.The influence of masonry material properties on mechanical properties of specimens was discussed.It provides a new idea and reference for the numerical calculation of Tibetan rubble masonry. |
