The Deformation Characteristics of a 40-m-Deep Excavation Supported by a Suspended Diaphragm Wall in Rock and Soil Composite Ground

2021 ◽  
Author(s):  
Gongchen Li ◽  
Qimin Li ◽  
Jian Wang ◽  
Jingmin Dong ◽  
Qiang Sun
Keyword(s):  
Diaphragm Wall ◽  
Deformation Characteristics ◽  
Deep Excavation ◽  
Composite Ground ◽  
Rock And Soil

scholarly journals The choice of soil models in the design of deep excavation in soft soils of Viet Nam

2018 ◽  
Vol 251 ◽  
pp. 04033
Author(s):  
Van-Hoa Nguyen ◽  
Nadezhda Nikiforova
Keyword(s):  
Computational Model ◽  
Measured Data ◽  
Diaphragm Wall ◽  
Viet Nam ◽  
Deep Excavation ◽  
Underground Construction ◽  
Soft Soils ◽  
Calculation Results

The use of diaphragm wall to protect the depth excavation is quite common in Viet Nam. Prediction of diaphragm wall deformations is required to choose the method of construction, and also for control of process of erection of an underground construction. Currently, there are many programs to calculate the deformation of the diaphragm wall, including software Plaxis. This paper considers the choice of a computational model for soils in the Hanoi - Viet Nam region of Mohr Coulomb (MC) and Hardening Soil (HS) and comparison of the calculation results with the measured data. Such investigations were conducted first.

Deformation characteristics of a 38 m deep excavation in soft clay

2011 ◽  
Vol 48 (12) ◽  
pp. 1817-1828 ◽  
Author(s):  
Guo B. Liu ◽  
Rebecca J. Jiang ◽  
Charles W.W. Ng ◽  
Y. Hong
Keyword(s):  
Soft Clay ◽  
Field Performance ◽  
Lateral Wall ◽  
Diaphragm Wall ◽  
Deep Excavation ◽  
Wall Panel ◽  
Soft Clays ◽  
Measured Ratio ◽  
Increasing Demand ◽  
Ground Settlements

To meet the increasing demand for underground space for economical development and infrastructural needs, more and more deep excavations have been constructed in Shanghai. In this paper, field performance of a 38 m deep multistrutted excavation in Shanghai soft clay is reported. The deep excavation was retained by a 65 m deep diaphragm wall. Inclinometers as well as settlement and heave markers were installed to monitor the performance of the deep excavation. This project provides an unusual opportunity to study the differential heaves of center columns and diaphragm walls during excavation. Because of the significant stress relief resulting from the 38 m deep excavation, maximum heaves of the center column and diaphragm wall panel were about 30 and 16 mm, respectively. The measured ratio δp/H (heave/final excavation depth) of column is less than 0.1% whereas the observed δp/H of the diaphragm wall panel is about 0.04%. The maximum distortion between the column and the diaphragm wall panel is smaller than 1/500, which is within the limit range proposed by Bjerrum in 1963. Owing to careful construction control, stiff strutting system, and compaction grouting, the measured lateral wall deflections and ground settlements at this site are generally smaller than other shallower excavations in soft clays in Shanghai, Singapore, and Taipei.

scholarly journals ANALISIS DAMPAK PEMBUKAAN GALIAN UNTUK CONNECTING BASEMENT TERHADAP BANGUNAN EKSISTING DENGAN METODE FINITE ELEMENT

2021 ◽  
Vol 5 (2) ◽  
pp. 401
Author(s):  
Della Amelia ◽  
Inda Sumarli ◽  
Ali Iskandar
Keyword(s):  
Finite Element ◽  
Ground Surface ◽  
Model Material ◽  
Diaphragm Wall ◽  
Existing Buildings ◽  
Deep Excavation ◽  
Allowable Limit ◽  
Finite Element Program ◽  
Existing Building ◽  
Static Conditions

In a deep excavation construction that adjacent to the existing buildings there is a concern that it will have a bad impact or effect on adjacent buildings.  The effect of deep excavation induced deformation of the existing structures due to ground movements and ground surface settlement behind the wall which can cause a tilt of the building. The objective of this study is to observe the effect of deep excavation (7 storey basement) adjacent to the existing buildings with 7 and 5 storey basement located in South Jakarta. The basement is connected to the basement of the existing building so that the effect of diaphragm wall opening for connecting basement towards the substructures of the existing building is observed. This study was conducted by observing the deformation that occurs in the diaphragm of the existing building, and also observing the internal forces acting on the basement floors slabs of the existing buildings. Observations were made using a three-dimensional finite element program with the most commonly used material model for analysis of deep excavation, The Hardening Soil Model. The analysis was performed with drained conditions with phreatic calculation type and only calculated the static conditions. Results indicate that the deflection that occurs after the final stage of excavation is still within the allowable limit according to the SNI 8460:2017, which is less than 14 centimeters on the diaphragm wall of the existing buildings. Keywords: Deep Excavation; Connecting Basement; Diaphragm Wall; Hardening Soil; Finite Element AbstrakPada suatu konstruksi galian dalam yang berdekatan dengan suatu bangunan lain dikhawatirkan akan memberikan dampak atau efek yang buruk terhadap bangunan di sekitarnya. Efek dari galian dalam tersebut menyebabkan terjadinya deformasi pada struktur dari bangunan di sekitarnya akibat dari pergerakan tanah dan penurunan permukaan tanah di belakang dinding yang dapat menyebabkan bangunan tersebut menjadi miring. Tujuan dari penelitian ini yaitu untuk mengamati pengaruh pekerjaan galian dalam (basement dengan 7 lantai) yang berdekatan dengan bangunan sekitar dengan basement 5 lantai dan 7 lantai yang berlokasi di Jakarta Selatan. Basement yang dimodelkan terkoneksi dengan basement dari bangunan eksisting sehingga diamati pengaruh bukaan dinding diafragma untuk connecting basement terhadap struktur bawah bangunan eksisting. Penelitian ini dilakukan dengan melihat deformasi yang terjadi pada dinding diafragma dari bangunan eksisting, dan juga mengamati gaya-gaya dalam yang bekerja pada pelat lantai basement dari bangunan eksisting. Pengamatan dilakukan dengan menggunakan program elemen hingga tiga dimensi dengan model material yang paling umum digunakan yaitu Hardening Soil untuk analisis galian dalam. Analisis dilakukan dengan kondisi drained dengan tipe kalkulasi phreatic serta hanya memperhitungkan keadaan static. Hasil menunjukkan bahwa defleksi yang terjadi setelah tahapan terakhir pekerjaan galian dalam yaitu masih dalam batas yang diijinkan menurut SNI 8460:2017 yaitu dibawah dari 14 cm pada dinding diafragma bangunan eksisting. 

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