Khi thi công tầng hầm cho các công trình nhà cao tầng, hầu hết các công trình đều được phân tích, tính toán theo mô hình 2D do thời gian phân tích nhanh và đơn giản tuy nhiên chuyển vị và độ lún nền thường sai lệch và thường lớn hơn rất nhiều so với kết quả quan trắc. Bài viết phân tích chuyển vị, mô men tường vây giữa mô hình 3D&2D có xét đến tính bất đẳng hướng của vật liệu tường vây. | PHÂN TÍCH CHUYỂN VỊ MÔ MEN TƢỜNG VÂY GIỮA MÔ HÌNH 3D amp 2D CÓ XÉT ĐẾN TÍNH BẤT ĐẲNG HƢỚNG CỦA VẬT LIỆU TƢỜNG VÂY LÊ BÁ VINH NGUYỄN NHỰT NHỨT TÔ LÊ HƢƠNG CHÂU QUANG TÖ Analysing the diaphragm wall deflection and bending moments between 3D amp 2D modeling taking into account of anisotropy of the wall materials Abstract In fact the diaphragm wall design is mostly performed by 2D analysis due to the simple and quick time analysis but the wall deflection and ground settlement are usually defferent from and much larger than the monitoring data. Out-of-plane bending moment M22 of diaphragm wall is not analyzed in 2D models normally the design will omit checking the flexural resistance of diaphragm wall in the direction out-of-plane or assuming M22 to check allowable capacity. In this study the author chooses Ben Van Don commercial apartment building in District 4 Ho Chi Minh City for analysis. The analysis is performed by changing the wall thickness from 500 1000 mm corresponding to the excavation depth varying from 2 4 basements the panel lengths from and determining the anisotropic ratio of the wall material k E2 E1 due to the horizontal stiffness of the wall is reduced because of the construction joints of the individual panels by back analysis deflection of the 3D volume panel models and 3D volume continuum models. This anisotropy ratio will be the input parameter for 2D volume anisotropic model which the wall is performed by the volume element according to the Jointed Rock Model JRM . The analysis results show that the relative difference in deflection bending moment M11 of 3D amp 2D analysis is quite large and increases when the wall thickness increases corresponding to the excavation depth. Especially that this difference is almost independent of the panel module length while the excavation depth increases the wall deflection difference of the 3D volume panel model and the 2D volume anisotropic model is not almost affected by the anisotropy of .
