fa اثر بارگذاری انفجار روی پایداری رمپ قره چنگول در معدن سرب و روی زه‌آباد ژئوتکنیک (مکانیک خاک و سنگ) Geotecnic مقاله پژوهشی Original Research <span style="font-family:b lotus;"><span style="font-size:10.0pt;">انفجار</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">و</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">لرزش‌های</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">حاصل</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">از</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">آن</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">در</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">مقایسه</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">با</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">ساختارهای</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">زمین‌شناسی</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">و</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">آب</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">زیرزمینی،</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">به‌دلیل</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">قابلیت</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">کنترل</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">بهتر</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">آن،</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">تأثیر کم‌تری</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">در</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">ناپایداری</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">حفریات زیرزمینی</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">دارند. عدم</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">اجرای</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">اصولی</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">فرآیند</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">انفجار،</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">ممکن</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">است</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">منجر</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">به</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">آسیب</span></span><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">‌</span></span></span><span style="font-family:b lotus;"><span style="font-size:10.0pt;">های</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">جدی</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">شود</span></span><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">.</span></span></span><span style="font-family:b lotus;"><span style="font-size:10.0pt;"> در این تحقیق مدل</span></span><span style="font-family:b lotus;"><span style="font-size:10.0pt;">‌</span></span><span style="font-family:b lotus;"><span style="font-size:10.0pt;">سازی روی رمپ قره چنگول معدن سرب و روی زه‌آباد در برابر بارهای انفجاری انجام شده است. این معدن در جنوب روستای زه‌آباد واقع در70&nbsp; کیلومتری شمال شهرستان قزوین در بخش طارم سفلی واقع</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">است.</span></span> <span style="font-family:b lotus;"><span style="font-size:10.0pt;">به‌منظور به‌دست آوردن خواص فیزیکی و مکانیکی سنگ‌های در برگیرنده رمپ و پارامترهای مقاومت برشی ناپیوستگی‌ها، آزمایش‌هایی شامل آزمایش‌های تک‌محوری، سه‌محوری، برزیلی، برش مستقیم، تعیین وزن مخصوص و سرعت امواج طولی انجام شد.&nbsp; هم‌چنین برای شبیه‌سازی شرایط پیچیده حاکم بر فرایند انفجار، </span></span><span style="font-family:b lotus;"><span style="font-size:10.0pt;">با توجه ناپیوسته بودن محیط، برای </span></span><span style="font-family:b lotus;"><span style="font-size:10.0pt;">مدل‌سازی عددی از نرم افزار المان مجزای </span></span><span dir="LTR"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">UDEC</span></span></span><span style="font-family:b lotus;"><span style="font-size:10.0pt;"> استفاده شد. در انجام یک تحلیل دینامیکی ابتدا باید مدل در حالت استاتیکی به تعادل برسد. بعد از تعریف شرایط مرزی جاذب، بارهای دینامیکی بر اساس مدت زمان تعریف شده به مدل وارد می‌شود. در بحث پایداری معادن و فرآیند انفجار، بار دینامیکی حاصل از آن اغلب به‌صورت یک پالس به مدل اعمال می‌شود. با وارد کردن بار دینامیکی و در نظر گرفتن سایر تغییرات یاد شده نسبت به تحلیل&nbsp; استاتیکی، می‌توان پاسخ دینامیکی فضای زیرزمینی را تحت بار لرزشی انفجار و یا زلزله پیش‌بینی کرد. برای این منظور موج ضربه&nbsp; ناشی از انفجار به‌صورت پالس نمایی با فشار بیشینه 41/4 مگاپاسکال و پهنای زمانی 7/0 تا 7 میلی‌ثانیه به مرز سمت چپ مدل اعمال شد. نتایج حاصل از تحلیل عددی نشان می‌دهد که در حالت استاتیکی فضای زیرزمینی مورد نظر پایدار است و بلوکی ریزش نمی‌کند. بعد از اعمال بار حاصل از انفجار نتایج نشان می‌دهد،&nbsp; رمپ پایدار می‌ماند و نیازی به نصب سیستم نگه‌داری نیست و در اطراف رمپ موردنظر ریزشی صورت نمی‌گیرد.&nbsp;</span></span><br> &nbsp; <strong>Introduction</strong><br> Unsystematic execution of blasting process may result in serious damages. Blasting is a very complex process and almost all of blast designs are made based on empirical relations resulting from trial and error. In recent decades, considerable development of numerical methods has been made possible to achieve high accuracy study of blast effects on surface and subsurface structures. Among these methods are boundary element method, finite difference method and finite element method. It should be mentioned that there is currently no software which might be able to completely simulate blast process. But the UDEC software is able to simulate different aspects of this phenomenon through simplification and focusing on each aspect.&nbsp; Therefore, the UDEC software was selected. In the present study, the modeling&nbsp; has been performed for Ghareh Changool ramp of Zehabad Zinc and Lead Mine against blast loads.<br> <strong>Material and methods</strong><br> Zehabad Ore deposit is located around 2 km south of&nbsp; Zehabad Village of Tarom Sofla County, 56 km to northwest of Qazvin at 49˚ 25&#39; east longitude and 36˚ 28&#39; north latitude.<br> The formation surrounding the ore deposit is generally made up of pyroclastics, lavas and sedimentary rocks of Eocene age (Karaj Formation) which have been divided into 22 stratigraphic units. Lithological composition of the tuff units are often rhyolithic to dacitic and the lava units are consisted of rhyolite, dacite and andesite.<br> To&nbsp; accomplish this study, we took rock blocks from Ghareh Changool ramp. Then, the blocks were cored in the laboratory to provide cylindrical samples for doing uniaxial compressive, triaxial, Brazilian and direct shear tests. Physical and mechanical properties of the tuff samples were determined according to ISRM standards.&nbsp;<br> In the present study, field studies were done to calculate strength parameters and properties of the joints.&nbsp; Based on these studies, three major joint sets were determined. In order to obtain the shear strength parameters of the joints, the cylindrical samples of andesitic tuff were molded by concrete and direct shear test was done on all of the joints according to ASTM D 4554.<br> <strong>Results and discussion</strong><br> To simulate the complex conditions of blast process, we used the discrete element software of UDEC for numerical modeling considering the discontinuity of the medium. To do a dynamic analysis, first the model should come to equilibrium in the static state. The space considered to be modeled in the study was a horse-shoe-shaped ramp with 4 m base, 4 m height and 1.5 m arc radius which was located in rocky medium consisting of tuff.&nbsp; The height of overburden above the roof of the ramp was about 190 m. The dimensions of the model in UDEC was 20*20 m². The behavioral model considered for the rock blocks and discontinuities were the elastic isotropic and surface contact of the joint (elasto-plastic) associated with Coulomb sliding failure, respectively. After defining the absorbing boundary conditions, the dynamic loads were applied to the model based on the defined time period. In mines stability and blasting process, the dynamic load resulting from the blast is often applied to a model as a pulse. By application of dynamic load and considering the other mentioned variations with respect of static analysis, the dynamic response of underground space could be estimated under vibration load of blast or earthquake. To do this, the blast impact wave was applied to the left side of the model as exponential pulse with maximum pressure of 4.41 MPa and time width of 0.7 to 7 msec. The results of the numerical modeling in static analysis indicated that no block would fall (Fig. 1). After application of the blast load, the results showed that there was no falling around the ramp (Fig. 2).<br> <strong>Conclusion</strong><br> 1. In static condition, after initial equilibrium no block was fallen into the ramp, regarding the blocks&rsquo; magnification plots, as a result the ramp was stable in the static loading.<br> 2. In dynamic loading case, considering the displacement plots&nbsp; around the ramp and the low values of these displacements, as well as, magnification plot of&nbsp; the blocks 40 msec after the blast it can be said that no block was fallen into the ramp. Therefore the ramp was stable in the dynamic loading case and there was no need to install support system.&nbsp;<a href="./files/site1/files/133/1Extended_Abstracts.pdf">./files/site1/files/133/1Extended_Abstracts.pdf</a> معدن سرب و روی زه‌آباد, رمپ قره چنگول, بارگذاری انفجار, پایداری, تحلیل دینامیکی, مدل‌سازی عددی.  Zehabad lead and zinc mine, Ghareh Changool ramp, blast loading, stability, dynamic analysis, numerical modeling. 339 364 http://jeg.khu.ac.ir/browse.php?a_code=A-11-1372-4&slc_lang=fa&sid=1 Fatemeh Abtahi فاطمه ابطحی f.abtahi14@gmail.com 10031947532846003890 10031947532846003890 Yes Imam Khomeini International University دانشگاه بین المللی امام خمینی (ره) Mehdi Hosseini مهدی حسینی meh_hosseini18@yahoo.com 10031947532846003891 10031947532846003891 No Imam Khomeini International University دانشگاه بین المللی امام خمینی (ره) Akbar Shah hosseini اکبر شاه حسینی akbarshahhosseini@gmail.com 10031947532846003892 10031947532846003892 No M. Sc. in Zehabad Zinc and Lead Mine معدن سرب و روی زه آباد