Abstract Building with masonry is based on the experience of many centuries. Although this design is used worldwide, knowledge about the material behaviour of masonry is still subject to uncertainties. The determination of safety of these structures against earthquakes is a complex challenge. For instance it depends on the resistance of the structure, the seismic action and on many uncertain structural details. One of the key parameters regarding the resistance is the shear strength of the masonry. A series of tests on mortar prisms according to EN 1015-11 was performed in which the mortar properties were varied in order to measure bending and compressive strength. In a second test program, the shear strength of the masonry was tested according to EN 1052-3. Shear triplets were made to establish the shear strength variation due to deliberate variation of the mortar properties. In addition, for both tests on mortar prisms and tests on shear triplets, descriptive statistical parameters were calculated and an attempt was made to describe the datasets with probabilistic distributions for further dimensioning and stochastic assessments.
Keywords Shear strength – Coefficient of friction – Old masonry
摘要 砌體建筑物是基于許多世紀(jì)以來的經(jīng)驗(yàn)。盡管這一設(shè)計(jì)被廣泛使用,但是了解到的關(guān)于砌體材料的性能依然存在不確定性。這些結(jié)構(gòu)在抗震中的安全性更是一個(gè)復(fù)雜的挑戰(zhàn)。比如，它取決于結(jié)構(gòu)的抗力、地震活動(dòng)和許多不確定的細(xì)部結(jié)構(gòu)。其中最關(guān)鍵的受力因素便是砌體的剪力。按照EN 1015 - 11對(duì)砂漿棱柱進(jìn)行一系列的試驗(yàn)，在不同強(qiáng)度的砂漿下，測(cè)得砌體的抗彎和抗壓強(qiáng)度。在接下的試驗(yàn)中，按照EN1052-3測(cè)得砌體的標(biāo)準(zhǔn)抗剪強(qiáng)度。進(jìn)行三軸剪切試驗(yàn)，得出在不同砂漿強(qiáng)度下砌體的抗剪強(qiáng)度。此外，對(duì)于砂漿棱柱試驗(yàn)和三軸剪切試驗(yàn)，都采用了描述性統(tǒng)計(jì)參數(shù)進(jìn)行計(jì)算。更有人企圖作進(jìn)一步的尺寸和隨機(jī)評(píng)估的概率分布描述來進(jìn)行數(shù)據(jù)收集。
關(guān)鍵詞 剪切強(qiáng)度-摩擦系數(shù)-舊磚石
1 引言
砌體是一種典型的承壓型建筑材料，但其剪切強(qiáng)度和抗彎承載力較低。這使得無筋砌體建筑十分有必要進(jìn)行力學(xué)性能的分析，特別是對(duì)老舊的砌體建筑，以及進(jìn)行合適的評(píng)估、分析和改造。
通常的設(shè)計(jì)和規(guī)范都特定采用歐洲標(biāo)準(zhǔn)（EC）。對(duì)于砌體結(jié)構(gòu)，規(guī)范和設(shè)計(jì)方面的規(guī)定采用EC6[1]。極限狀態(tài)分為三種情況：1.砌體豎向承載極限狀態(tài)，2砌體剪切承載極限狀態(tài)；3砌體抗彎承載極限狀態(tài)。其中起控制因素的是抗剪承載力和抗彎承載力，尤其是在無筋砌體結(jié)構(gòu)中。而主要的水平荷載是由風(fēng)荷載或地震作用引起的。