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为研究不同化学溶液对砂岩力学性质及能量特征的影响,采用不同的水化学溶液对砂岩试样进行腐蚀,利用WDT-1500多功能材料试验机对化学腐蚀后饱和状态与自然状态的试样进行常规三轴压缩试验。试验结果表明:化学腐蚀后砂岩试样的强度及其抗变形能力呈现不同程度的劣化;化学腐蚀后砂岩试样的峰值应变小于相同围压下自然状态试样的峰值应变,与单轴压缩条件下不同,这可能是由于围压和化学溶液共同作用的结果;砂岩试样的似软化系数与围压之间呈现负相关性,同时,其降低速率随着围压的增加而降低。砂岩试样峰值前吸收的能量绝大部分是以可释放弹性应变能Ue形式储存下来的,而化学腐蚀后砂岩试样以Ue形式储存下来的能量占其总吸收应变能的百分比却有所下降;同时,围压与试样的可释放应变能/应变能比值之间呈负相关性,而与耗散能/应变能比值存在正相关性;岩石脆性指标修正值呈现不同程度的增加,试样的脆性减弱延性增强,即塑性变形增加,塑性变形与耗散能之间具有很好的线性特征。溶液的pH值、浓度和化学成分对砂岩试样峰值处各部分应变能的影响显著。
In order to study the effect of different chemical solutions on the mechanical properties and energy characteristics of sandstones, sand samples were corroded by different aqueous chemical solutions. The saturated and natural samples after chemical etching were tested by WDT-1500 multifunctional material testing machine Conventional triaxial compression test. The results show that the strength of the sandstone sample and the anti-deformation ability of the sandstone sample deteriorate to some extent after chemical etching. The peak strain of the sandstone sample after the chemical etching is smaller than the peak strain of the natural sample under the same confining pressure, This may be due to the interaction between confining pressure and chemical solution. The softening coefficient of sandstone sample is negatively correlated with the confining pressure, and the rate of decrease decreases with the increase of confining pressure. Most of the energy absorbed before the peak of the sandstone sample is stored in the form of the releasable elastic strain energy Ue, while the percentage of the total energy absorbed by the sandstone sample stored in Ue after chemical etching is decreased At the same time, there is a negative correlation between the confining pressure and the releasable strain energy / strain energy ratio of the specimen, but positively correlated with the ratio of the dissipation energy / strain energy. The correction value of the brittleness index of the rock increases with different degrees. The ductile ductile ductile ductile ductile ductile ductile ductile ductile brittle ductile ductile ductile ductile brittle ductile ductile ductile brittle ductile ductile ductile ductile brittle ductile ductile ductile brittle ductile ductile ductile brittle ductile ductile ductility The pH value, concentration and chemical composition of the solution have significant influence on the strain energy of each part of the sandstone sample.