Pembinaan terowong di kawasan bandar semakin popular akibat keterhadan tanah di metropolis. Walaubagaimanapun, pembinaan terowong di kawasan perbandaran melibatkan mekanisme yang kompleks disebabkan interakasi antara terowong dan tanah. Pergerakan tanah yang disebabkan oleh pembinaan terowong berpotensi mengancam kestabilan struktur permukaan ataupun subpermukaan. Oleh itu, pembinaan projek terowong yang berskala besar seperti KVMRT, reka bentuk terowong yang mempunyai anggaran tepat tentang perubahan struktur tanah dan simulasi geoteknik yang realistik adalah penting. Dalam kajian ini, penyiasatan ciri-ciri sub-permukaan tanah bagi Formasi Bukit Kenny telah dijalankan dengan menghasilkan model tanah 3 dimensi, model terowong dan keratan rentas subpermukaan tanah melalui interpolasi spasial data lubang jara melalui kaedah Inverse Distance Weighted (IDW). Enam keratan rentas tanah telah dikenalpastikan berdasarkan input daripada model terowong, konfigurasi terowong berkembar dan ketersediaan data pergerakan tanah disebabkan oleh pembinaan terowong. Model konseptual untuk pemodelan secara unsur terhingga telah dibangunkan berdasarkan profil tanah dan parameter lapisan tanah yang dikenalpastikan daripada keratan rentas tanah yang terpilih. Parameter kekuatan dan kekukuhan tanah untuk model Pengerasan Tanah (HS) telah ditentukan dengan penggunaan data yang didapati daripada penyiasatan tapak, ujian tanah di situ dan makmal serta korelasi empirikal berkaitan dengan nilai Ujian Penusukan Piawai (SPT-N). Keberkesanan korelasi empirikal telah dinilaikan oleh analisis kembali dalam 2 dimensi analisis unsur terhingga yang menggunakan kaedah kontraksi pelapik. Simulasi pembinaan terowong kembar menggunakan parameter HS yang diperolehi daripada korelasi empirical yang terpilih meramalkan keputusan yang selari dengan pergerakan tanah yang dipantau dengan penggunaan nilai nisbah kontraksi dari 0.3% hingga 0.92%.
_______________________________________________________________________________________________________
Urban tunnelling is becoming more popular due to the limitation of land use in metropolis. However, urban tunnelling are always associated with difficulties and involved with complex mechanism due to its interaction between tunnels and ground. The volume loss during the tunnelling excavation has led to ground deformation which may potentially damage the adjacent surface or subsurface structures. Thus, for large scale underground construction like KVMRT, tunnel design with proper estimation of ground deformation and realistic geotechnical simulation is essential. In this study, the subsurface characterization of tunnel excavation section in Kenny Hill Formation was conducted to develop 3D ground model, tunnel filtered model and ground section through spatial interpolation of borehole data using Inverse Distance Weighted method (IDW). Six greenfield ground sections were selected based on input of tunnel filtered models configuration of tunnels and availability of tunnelling induced ground movement data. The conceptual models for finite element modelling were developed based on the soil profiles and corresponding soil parameters determined from ground sections. The strength and stiffness parameters for Hardening Soil (HS) model were established using data from site investigation, in situ and laboratory test and empirical correlation with standard penetration test N numbers(SPT-N). The effectiveness of empirical correlation is determined by back-analysis of twin tunnels excavation in 2D finite element analysis using lining contraction method and verified with monitored ground movement data. The numerical back-analysed results of twin tunnels excavation simulation using HS parameters obtained from selected empirical correlation showed good agreement with construction-monitored ground movements with application range of values of contraction ratio from 0.3% to 0.92%.
Twin tunnel interaction mechanism in kenny hill formation using finite element analysis / Tan Yih Ken