High-density bimodal bentonite blends for hydraulic sealings at the Ibbenbüren coalmine
High-density bimodal bentonite blends for hydraulic sealings at the Ibbenbüren coalmine
复制标题
用于伊本比伦煤矿液压密封的高密度双峰膨润土混合物
作者：
F. Wolters;W. Baille;K. Emmerich;Evan Schmidt;C. Wolters;F. Königer;J. Kunz;V. Krase;M. Schellhorn
德国m<s:1> nsterland ibbenb<s:1> ren煤矿的两座高压挡水坝在现有矿区进一步开采所产生的诱发张力下必须可靠运行。将新型屏障的承载功能与密封功能分离，开发新型密封材料。该项目采用了一种由膨润土和夹层等势层（SANDWICH）组成的创新多层密封系统，支持均匀膨胀和密封，不受地层水的影响（n<s:1> esch等，2002）。在压实的膨润土样品和膨润土/砂混合物上进行了应变控制的膨胀压力测试，以确保膨胀压力发展的充分潜力。当干密度在1.45 g/cm³~ 1.67 g/cm³之间时，等体积下的测量结果表明，100%膨润土样品的膨胀压力在1.04 ~ 1.8 MPa之间。应变控制式测压仪对零应变和逐步施加至2%应变的测试表明，在最大施加应变下存在足够大的膨胀压力。
Abstract The two high-pressure water-retaining dams at the Ibbenbüren coalmine in Münsterland (Germany) have to perform reliably under the induced tension caused by further exploitation of the current mining area. The load-bearing and the sealing functions of the new barriers were separated and new sealing materials were developed. An innovative multilayer sealing system of bentonite and sandwiched equipotential layers (SANDWICH) supporting homogeneous swelling and sealing, independent of formation water (Nüesch et al., 2002), was applied in this project. A testing program of strain-controlled swelling pressure tests on compacted bentonite specimens and on a bentonite/sand mixture was conducted to ensure an adequate potential for swelling-pressure development. The measurements under constant volume for dry densities between 1.45 g/cm³ and 1.67 g/cm³ showed an evolving swelling pressure between 1.04 and 1.8 MPa for 100% bentonite samples. Strain-controlled oedometer tests for zero strain and step-wise applied strain up to 2% revealed that a sufficient magnitude of swelling pressure existed at maximum applied strain.