ارزیابی نقش فشار تزریق در فیلتراسیون دوغاب‌های پایه سیمانی در چند مثال از سنگهای نرم

نوع مقاله: مقاله پژوهشی

نویسندگان

1 گروه زمین‌شناسی مهندسی/ بخش زمین شناسی/ دانشگاه تربیت مدرس/تهران / ایران

2 استاد، گروه زمین‌شناسی مهندسی، دانشکده علوم پایه، دانشگاه تربیت مدرس، تهران، ایران

چکیده

عوامل متعددی در فیلتر‌شدن دوغاب‌های سیمانی نقش دارند که در چند دسته قابل ارزیابی هستند. این عوامل مهم و اساسی شامل خصوصیات رفتاری دوغاب، سیمان و مصالح تزریق، محیط تزریق و اندرکنش دوغاب با آن و فشار تزریق می‌باشند. در بین عوامل بالا، تحقیقات کمتری در مورد نقش فشار تزریق در فیلتر شدن دوغاب دیده می‌شود. تحقیق نشان می‌دهد، سرعت افزایش فشار تزریق در مقدار جذب سیمان و نفوذ آن تاثیر چشمگیری دارد. در این تحقیق نتایج بررسی داده‌های مقاطع تزریق در سنگ از دو طرح سد‌سازی مورد بررسی قرار گرفته است. بعبارت دیگر دو دیدگاه تزریق با فشار متغیر و ثابت مورد بررسی قرار گرفته است. در حالت فشار متغیر وجود پله‌های افزاینده فشار می‌تواند سبب فرسایش کیک دوغاب در هر مرحله از تشکیل آن و نفوذ بیشتر دوغاب می‌شود. در تزریق با فشار ثابت، فشار در زمان کمی به مقدار حداکثر طرح شده می‌رسد و نتایج نشان می‌دهند نفوذ دوغاب کمتر بوده است. با بکارگیری روش تدریجی افزایش فشار تزریق، نفوذ دوغاب بدلیل فرسایش کیک دوغاب بهبود یافته و هزینه‌های آب‌بندی پی سد‌ها، تونل‌ها و سازه‌هایی که نیاز به تزریق سیمان دارند بدلیل نفوذ بیشتر کاهش پیدا می‌کند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Evaluation on the Role of Grouting Pressure in Filtration of Cement- based Grouts According to Examples of Soft Rocks

نویسندگان [English]

  • Mohammad Hassan Nazari 1
  • A. Uromeihy 2
1 engineering geology department/ geology section/Tarbiat modaress university/ Tehran/Iran
2 Professor, Department of Geology, Faculty of Basic Sciences, Tarbiat Modares University, Tehran, Iran
چکیده [English]

There are several outstanding factors engaged in the cement grouts filtration. These factors can be evaluated from some aspects including the characteristics of the grout, cement and grouting materials, grouting environment, interaction between the grout and environment and grouting pressure among which fewer studies have been performed on the role of the grouting pressure in the grout filtration. In this research practical results of cement grouting have been reviewed in two dam projects as examples. The results depict that the increase in the grouting pressure considerably affects the rate of cement take and penetration. In practice, the cement penetration into the rock is higher when the grouting pressure is variable. This is vice versa under constant grouting pressure. In other words, the increasing steps of grouting pressure may erode the grout cake at each stage. This leads to optimal penetration of the grout and decreases the watertightening costs of the dam foundation, tunnels and structures requiring cement grouting.

کلیدواژه‌ها [English]

  • Grouting pressure
  • Filtration
  • penetration
  • filter cake

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