CAJ | 학술논문

随着核废料处置和地下煤气化等工程的发展，高温岩石力学问题成为目前岩石力学界关注的焦点之一。为研究温度和尺寸对岩石抗拉强度的影响规律，对20℃(室内常温)～800℃范围5种温度水平下，岩样厚径比为0.5～1.0范围的5种尺寸的红砂岩圆盘试样进行室内巴西劈裂抗拉强度试验。试验结果表明：圆盘的荷载位移曲线表现出显著的脆性特征，温度对曲线的发展趋势起主导作用，而岩样尺寸的影响相对较弱；红砂岩的抗拉强度随着温度的升高先逐渐增大后又急剧减小，在400℃时达到最大值；相同温度下红砂岩的抗拉强度与圆盘厚径比均呈现线性减小的关系，并提出相应的经验公式(σt =－Aλ+B)以描述其变化规律，其中，参数A反映了材料受尺寸影响的显著程度，随着温度的升高，参数A先减小后有所增大，400℃时尺寸效应最不明显，参数B为圆盘尺寸无限小(即理想平面状态时)材料的抗拉强度值，随着温度的升高，先缓慢增大后又逐渐减小，在400℃时达到最大值。
수착핵폐료처치화지하매기화등공정적발전，고온암석역학문제성위목전암석역학계관주적초점지일。위연구온도화척촌대암석항랍강도적영향규률，대20℃(실내상온)～800℃범위5충온도수평하，암양후경비위0.5～1.0범위적5충척촌적홍사암원반시양진행실내파서벽렬항랍강도시험。시험결과표명：원반적하재위이곡선표현출현저적취성특정，온도대곡선적발전추세기주도작용，이암양척촌적영향상대교약；홍사암적항랍강도수착온도적승고선축점증대후우급극감소，재400℃시체도최대치；상동온도하홍사암적항랍강도여원반후경비균정현선성감소적관계，병제출상응적경험공식(σt =－Aλ+B)이묘술기변화규률，기중，삼수A반영료재료수척촌영향적현저정도，수착온도적승고，삼수A선감소후유소증대，400℃시척촌효응최불명현，삼수B위원반척촌무한소(즉이상평면상태시)재료적항랍강도치，수착온도적승고，선완만증대후우축점감소，재400℃시체도최대치。
In recent years,issues of rock mechanics under high temperature have been highlighted with the rapid development of nuclear waste treatment and underground coal gasification projects,which has become a focus in the rock mechanics field currently. In order to investigate the influence of temperature and sample size on the tensile strength,Brazilian splitting tensile strength tests were conducted on sandstone disc samples with five kinds of temperature levels ranging from 20℃ to 800℃ and five kinds of thickness-diameter ratios ranging from 0.5 to 1.0. Experimental results show that loading-displacement curves of sandstone discs appear remarkable brittle characteristics. And the temperature plays a leading role in the development trend of the curves,while the effect of sample size is relatively weak. With the increase of temperature,tensile strength first increases gradually and then decreases sharply,and reaches the maximum at 400℃. The tensile strength of sandstones under same temperature presents a linear attenuation relationship with the thickness-diameter ratio,and the corresponding experiential formula is put forward asσt =-Aλ +B. Here,the parameterA describes the prominent level of materials affected by the size,which decreases first and then increases with the increase of temperature,and the size effect is mostly unconspicuous at 400℃. The parameterB is the tensile strength value of materials when the sample size is infinitesimal to the ideal plane,which first increases slowly and then decreases gradually,with the maximum value also reaches at 400℃.