藏式毛石砌体抗压强度对其弹性模量和峰值应变预测

抗压强度、弹模和峰值应变是藏式毛石砌体力学性能的3个重要参数，由于砌块不规则性和砌筑工艺随机性的影响导致该类砌体抗压强度、弹模、峰值应变都较难直接获得。通过毛石砌块和泥浆黏材强度获得毛石砌体抗压强度，以抗压强度预测弹性模量和峰值应变是为了研究此类砌体变形特征和力学特性。采用西藏传统砌筑工艺砌筑8个毛石棱柱体试件，对棱柱体试件进行单轴压缩力学测试，获得毛石砌体抗压强度、弹模、峰值应变、位移-荷载曲线、破坏形态等。结合已有研究成果对该类砌体抗压强度表达式中砌块与泥浆相关影响系数进一步优化，以抗压强度预测其弹性模量、峰值应变。试验结果表明，该类砌体抗压强度、弹模、峰值应变较低且变形呈阶段性变形特征，位移-荷载曲线与其他类型砌体对比存在差异。以区间估计法和线性回归进行弹性模量和峰值应变预测并与其他类别毛石砌体对比发现吻合度较好。该结论可供该类砌体结构修复、加固和毛石砌体单轴压缩性能研究参考。

Prediction of elastic modulus and peak strain of Tibetan rubble masonry based on its compressive strength

Compressive strength, elastic modulus and peak strain are three important parameters for mechanical properties of Tibetan rubble masonry. The compressive strength of rubble masonry can be obtained from rubble masonry blocks and mud sticky materials, but the elastic modulus and peak strain of masonry are difficult to be obtained due to the irregularity of masonry blocks and the randomness of masonry process. The prediction of elastic modulus and peak strain by compressive strength is to study the deformation characteristics and mechanical properties of such masonry. Eight rubble masonry specimens were built by xizang traditional masonry technology. Uniaxial compression tests were carried out on the prismatic specimens to obtain the compressive strength, displacement-load curve and failure mode of rubble masonry. The correlation coefficient between block and mud in the expression of compressive strength was optimized, and the elastic modulus and peak strain were predicted by the compressive strength. The test results show that this kind of masonry has low compressive strength and stage deformation characteristics, and its displacement-load curve is different from that of other types of masonry. The predicted values of elastic modulus and peak strain are found to be in good agreement with those of other rubble masonry structures, and there is a strong correlation among them. This paper can be used as reference for the study of the uniaxial compression performance of rubble masonry.