(中南大學(xué) 資源與安全工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 亞臨界裂紋擴(kuò)展是巖體工程時(shí)間相依性的主要原因之一，利用Inston1342型電液伺服材料試驗(yàn)機(jī)，采用常位移松弛法分別進(jìn)行自然狀態(tài)以及飽水狀態(tài)下巖塊的亞臨界裂紋擴(kuò)展實(shí)驗(yàn)，獲得了兩種環(huán)境下巖石裂紋擴(kuò)展速率v 與應(yīng)力強(qiáng)度因子KI的關(guān)系及亞臨界裂紋擴(kuò)展參數(shù)，研究水對(duì)巖石亞臨界裂紋擴(kuò)展規(guī)律的影響，并對(duì)兩種環(huán)境下亞臨界裂紋擴(kuò)展參數(shù)進(jìn)行了對(duì)比分析。結(jié)果表明：兩種環(huán)境下巖石的lgKI-lgv有較好的線性規(guī)律，巖石的亞臨界裂紋擴(kuò)展速率與裂紋尖端應(yīng)力強(qiáng)度因子服從冪函數(shù)關(guān)系；在雙對(duì)數(shù)坐標(biāo)空間中，含飽和水試件的lgKI-lgv曲線位于空氣中試件lgKI-lgv曲線的左上角，含飽和水試件的曲線斜率較空氣中試件的減小，而截距增加。在同一應(yīng)力強(qiáng)度因子水平上，含飽和水試件的裂紋擴(kuò)展速度大，表明水加速了巖體亞臨界裂紋擴(kuò)展。該實(shí)驗(yàn)結(jié)果可為水化學(xué)作用下復(fù)雜巖體的穩(wěn)定性分析提供可靠依據(jù)。
關(guān)鍵字: 雙扭試件；常位移松弛法；水化學(xué)作用；亞臨界裂紋擴(kuò)展；應(yīng)力強(qiáng)度因子
（School of Resource and Safety Engineering, Central South University, Changsha 410083, China）
Abstract:Subcritical crack growth is one of the main causes of time-dependent behavior in rock mass engineering. By using Instronl 1342 type electro hydraulic servo test machine and adopting the double-torsion load-relaxation method at constant displacement, two groups of specimens, one immersed in groundwater and the other in air, were tested to study the relationship between the crack growth rate v and fracture toughness KI, and the parameters of subcritical crack growth in the two different environments were gotten. The influence of water on the subcritical crack growth mechanism was analyzed, and comparisons of the parameters of the growth of subcritical crack were made for the two different environments above-mentioned．The results show that the parameters of lgKI-lgv are in accord with linear rules, the relationship between subcritical crack growth velocity v and stress intensity factor KI agrees power function. In the double logarithmic coordinates space, the lgKI-lgv curves of those specimens in saturated water locate at the left coner above those of the specimens in air with smaller slope but larger intercept. In addition, the subcritical crack growth velocity of saturated water specimen is higher at the same stress intensity factor, which indicates that water speeds up the subcritical crack growth. Those results can provide reliable references to study the complicated rock mass stability under the effects of water.
Key words: double torsion specimen; constant displacement load relaxation method; chemical water-rock interaction; subcritical crack growth; stress intensity factor
