Study on Design and Construction Safety of Open-cut Structure of Railway Tunnels in Shallow Water-bearing Soft Soils

Author(s):  
Yi Yuan
2011 ◽  
Vol 99-100 ◽  
pp. 1166-1170 ◽  
Author(s):  
Yuan Hai Li ◽  
Ping Liu ◽  
Ji Qiang Liu ◽  
Xue Feng Han

The main purpose of this paper is to analyze the stability and safety problems of braced excavation enclosure, surrounding strata and side slope during construction of Shangshuijing station in Shenzhen Metro Line 5. The paper presents stability discrimination of the braced excavation and side slope by discussing their force and deformation regularity using Flac3D, and puts forward some project proposals about its design and construction. The results show that: (1) The stability coefficient of braced excavation enclosure becomes smaller because of biasing impact of side slope, but this project can meet the stability requirements, (2) The biasing impact of side slope has little influence on deformation of surrounding strata starting on the other side of braced excavation without slope, and (3) To ensure construction safety under condition of side slope, the braced excavation should be excavated starting from the zone far from the side slope, steel pipe can be used as assistant reinforcement at the corner of side slope if necessary.


2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Huier Xu ◽  
Shoude Li

Recent years have seen a great concern on the construction safety of the deep foundation pit with complicated geological conditions due to an increasing number of accidents. However, there are not, currently, sufficient research studies on the safety analysis of the deep foundation pit in water-rich soft soils. As a result, dynamic predictions of the safety risk during the whole construction process are inadequate due to the lack of research studies. Therefore, this paper presents an approach for the construction safety of the deep foundation pit in water-rich soft soils, which combines the building information modeling (BIM), the finite element analysis (FEA), and the finite difference method (FDM). By using BIM technology, the author attempts to establish a 3D information model and a bracing structure model. Based on the application programming interface and the C# language, the data conversion from BIM-ANSYS-FLAC3D is realized. The author then attempts to analyze the ground surface settlement and horizontal displacement during the excavation of the deep foundation pit through FLAC3D, and the purpose of which is to identify potential safety hazards so that reasonable control measures can be taken. The approach presented in this article has been validated in the Project of Qinhuai River Ship Lock. Since the excavation and the after-construction stages of this project have been completed smoothly, this approach has been proved valid and applicable.


2020 ◽  
Vol 3 (1) ◽  
pp. 59
Author(s):  
Sastrawinata Sastrawinata ◽  
Andryan Suhendra

Soft soil is commonly become the main problem in various types of construction processes. It causes a very big load distribution in soils that will affect the construction process that will take place.  Soft soils have a low bearing capacity which can result in loss, costs that become more expensive to construction safety, that is, structures that are made unable to stand stable and are not sturdy. This can be prevented by stabilizing soft soils using geotextile reinforcement. Geotextile material works using membrane effect method which only relies on its own tensile strength which can help to reduce the load distribution that occur on sof soils. In one of the road projects in Jakarta, road will be made with very soft soil subgrade. To reduce the load distribution, embankment is carried out on existing land with geotextile reinforcement in between. This geotextile material is proven to reduce the load distribution that occurs in soft soils so the value of the load distribution will be smaller. For more effective use, the geotextile used in this project must be placed at 0,2 metres height above the subgrade. AbstrakTanah lunak seringkali menjadi sumber masalah yang paling banyak terjadi pada berbagai jenis proses kontruksi. Tanah ini menyebabkan distribusi beban yang terjadi sangatlah besar sehingga akan berpengaruh terhadap proses konstruksi yang akan berlangsung. Tanah lunak mempunyai daya dukung yang sangat kecil yang dapat mengakibatkan kerugian, mulai dari kerugian biaya yang menjadi lebih mahal hingga keselamatan konstruksi, yaitu struktur yang dibuat tidak mampu berdiri stabil dan tidak kokoh. Hal ini dapat dicegah dengan menstabilisasi tanah lunak dengan menggunakan perkuatan geotekstil. Material geotekstil bekerja menggunakan metode membrane effect yang hanya mengandalkan kuat tariknya sendiri yang dapat membantu mengurangi distribusi beban yang terjadi pada tanah lunak. Pada salah satu proyek jalan di Jakarta, akan dibuat jalan dengan tanah dasar tanah yang sangat lunak. Untuk membantu dalam mengurangi distribusi beban yang terjadi, dilakukan penimbunan tanah di atas tanah eksisting dengan perkuatan geotekstil di antaranya. Material geotekstil ini terbukti dapat mengurangi distribusi beban yang terjadi pada tanah lunak sehingga nilai distribusi beban yang terjadi menjadi lebih kecil. Untuk penggunaan yang lebih efektif, letak geotekstil yang digunakan pada proyek ini harus diletakkan pada ketinggian 0,2 meter di atas tanah dasar.


Author(s):  
S. B. Pranesh ◽  
D. Sathianarayanan ◽  
G. A. Ramadass ◽  
E. Chandrasekaran ◽  
M. Murugesan ◽  
...  

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