本文選題：灰?guī)r + 酸腐蝕　； 參考：《巖土力學》2017年11期

【摘要】：地下水化學腐蝕在巖石圈中廣泛存在,而巖體也常因承受動荷載而變形破壞。為探究酸腐蝕后灰?guī)r的動態(tài)力學性質,將試樣分別在pH=3的NaCl和KHSO_4混合溶液中浸泡不同時間,通過核磁共振測試獲得了部分試樣的孔隙率、孔徑分布及成像灰度圖,并利用分離式Hopkinson壓桿開展了5種應變率的單軸沖擊試驗。結果表明:隨腐蝕時間增加,灰?guī)r孔隙率從自然狀態(tài)下的0.26%劇增到3.20%(腐蝕28 d),微孔隙尺度也同步增大;動態(tài)抗壓強度大幅劣化(30.3%),并可根據下降速率區(qū)分為2個階段,而其彈性模量和比能量吸收值則隨時間呈指數衰減。自然狀態(tài)和腐蝕后灰?guī)r的應變率響應規(guī)律基本一致:隨應變率增大,破壞模式由典型的劈裂破壞向拉剪混合、剪切破壞過渡,直至粉末狀破壞;抗壓強度和彈性模量近似線性增加,但自然狀態(tài)下二者對應變率的敏感程度較腐蝕后強烈。酸腐蝕對灰?guī)r動態(tài)承載能力和抗變形能力具有重要影響,在工程實踐中應加以考慮。
[Abstract]:Chemical corrosion of groundwater exists widely in lithosphere, and rock mass is often deformed and destroyed by dynamic load. In order to investigate the dynamic mechanical properties of limestone after acid corrosion, the samples were immersed in the mixed solution of NaCl and KHSO_4 of pH=3 for different time. The porosity, pore size distribution and image grayscale of some samples were obtained by nuclear magnetic resonance (NMR). The uniaxial impact tests of five strain rates were carried out using the split Hopkinson compression bar. The results show that with the increase of corrosion time, the porosity of limestone increases sharply from 0.26% in natural state to 3.20% (28 days after corrosion, the micropore scale also increases, and the dynamic compressive strength deteriorates to 30.3%, and can be divided into two stages according to the decreasing rate. However, the elastic modulus and specific energy absorption value decrease exponentially with time. The natural state is basically consistent with the strain rate response of the corroded limestone: with the increase of the strain rate, the failure mode changes from typical split failure to tensile shear, shear failure transition to powder failure; The compressive strength and elastic modulus increase linearly, but their sensitivity to strain rate in natural state is stronger than that after corrosion. Acid corrosion has an important influence on the dynamic bearing capacity and deformation resistance of limestone, which should be considered in engineering practice.
【作者單位】： 中國礦業(yè)大學深部巖土力學與地下工程國家重點實驗室;中國礦業(yè)大學力學與土木工程學院;
【基金】：國家重點基礎研究發(fā)展計劃(973)項目(No.2013CB036003) 國家自然科學基金(No.51579239,No.51374198)~~
【分類號】：TU45

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