يعد استخدام تقنية أنابيب الألياف الزجاجية (Fiber glass pipes) في تدعيم جبهة حفر الأنفاق من الطرق الفعالة جداً للحفاظ على استقرار جبهة الحفر, و بالتالي تخفيض هبوطات سطح الأرض و تشوهات جبهة الحفر و الحفاظ على سلامة العمال و الأليات المستخدمة في الحفر.
يقدم هذا البحث نتائج تحليل عددي بطريقة الفروقات المحدودة (برنامج FLAC3D) لسلوك جبهة حفر نفق سطحي مدعم بالأنابيب الطولية الزجاجية, حيث تم وضع موديل عددي ثلاثي الأبعاد و معايرته لبيان فعالية هذه التقنية و إجراء دراسة بارامترية لتحديد بارامترات التقنية الحدية (كثافة (عدد) الأنابيب (A) و طولها (L)). أظهرت النتائج أن تقنية التدعيم باستخدام الأنابيب الزجاجية تخفض الانتقالات (انتفاخ جبهة الحفر و هبوط سطح الأرض) بشكل واضح مما يزيد من استقرار الجبهة, و أن هذه الانتقالات تقل بزيادة طول الأنابيب و بزيادة كثافة الأنابيب المزروعة في جبهة الحفر حتى الوصول إلى الكثافة الحدية, و عند الوصول إلى الطول الحدي يجب تجديد الأنابيب للحفاظ على استقرار عملية الحفر.
Supporting tunnel face by Fiber glass pipes technology is an effective method to
maintain the stability of tunnel face, thus reducing surface settlements, face deformation
and maintaining the safety of the workers and the mechanisms used in tunneling.
This paper presents the results of finite-difference numerical analyses (FLAC3D program)
on the behavior of a shallow tunnel face reinforced by longitudinal fiber glass pipes. A 3D
numerical model has been calibrated and used to demonstrate the effectiveness of this
technique, and perform a parametric study to determine the critical reinforcements
parameters (the density (number of pipes)(A) and length (L)). The results indicate that the
face reinforcement technique using longitudinal fiber glass pipes can significantly reduce
the movements (face displacement and surface settlements), and thus improving the face
stability. These movements decrease by increasing the length of the pipes and increasing
the density of the pipes until reaching the critical density, and when we reach the critical
length, the pipes must be renewed to maintain the stability of the tunneling process.
References used
Atkinson,J.H., Potts,D.M. Subsidence above shallow tunnels in soft ground. Jnl. Geotech. Eng. Div., ASCE, GT4,PP. (1977), 307-325
LUNARDI, P. The influence of the rigidity of the advance core on the safety of tunnel excavation. Gallerie e grandi opere sotterranee, 52, (1997)
GALLI,G; G RIMALDI, A; LEONARDI, A .Three-dimensional modeling of tunnel excavation and lining . Computers and Geotechnics 31 (2004)
This paper presents and analyses the results of 2D and
3D numerical simulation conducted for the performance prediction
of TBM tunneling in clay soil.
This research deals with the study of the behavior of piles under the influence of seismic loads through (3D) modeling using FE-Method-program (ABAQUS) with special reference to the most important parameters affecting the displacements and internal f
In present investigation attempt has been made to study the bearing capacity and settlement
characteristics of footings subjected to central vertical load and resting on layered soil with
the help of model tests and with the application of finite e
This research study aims at investigating the potential benefits of using the reinforcement
to improve the bearing capacity and reduce the settlement of strip footing on clay. To
implement this objective, many numerical 2D-analyses by finite elemen
This research study aims at investigating the potential benefits of using the
reinforcement to improve the bearing capacity and reduce the settlement of strip footing on
clay. To implement this objective, many numerical 2D-analyses by finite elemen