Lateral displacement of soft ground under vacuum pressure and surcharge load

2011 ◽  
Vol 5 (2) ◽  
pp. 239-248 ◽  
Author(s):  
Chin-Yee Ong ◽  
Jin-Chun Chai
Keyword(s):  
Lateral Displacement ◽  
Vacuum Pressure ◽  
Soft Ground ◽  
Surcharge Load

scholarly journals Lateral displacement under combined vacuum pressure and embankment loading

Géotechnique ◽  
2013 ◽  
Vol 63 (10) ◽  
pp. 842-856 ◽  
Author(s):  
J. CHAI ◽  
C.Y. ONG ◽  
J.P. CARTER ◽  
D.T. BERGADO
Keyword(s):  
Lateral Displacement ◽  
Vacuum Pressure

Study on the Lateral Displacement of Super-Long Pile under a Asymmetrical Surcharge Load in Soft Clay

2014 ◽  
Vol 580-583 ◽  
pp. 733-737
Author(s):  
Qi Li ◽  
Xiao Li Lu
Keyword(s):  
Lateral Displacement ◽  
Soft Soil ◽  
Soft Clay ◽  
Three Dimensional ◽  
Influence Factors ◽  
Major Influence ◽  
Small Contribution ◽  
Practical Engineering ◽  
Surcharge Load ◽  
Building Load

The pile will have a large lateral displacement in soft soil under the role of heaped load. Based on Biot consolidation theory, combined with a certain highway project, a three-dimensional FEM model is established, the process that the soil lateral deformation under heaped load lead to the pile side displacement was simulated. On the ground of the former result, the influence factors for the displacement of pile top and the pile displacement field distribution are analysed. The results show that, the building load area, load grade and the distance from loading area to pile have a major influence on the pile side displacement. On the other hand, the load on pile top have a very small contribution for stability of anti side displacement. The buildings nearby the area of pile foundation should be given attention in practical engineering.

Vacuum consolidation and its combination with embankment loading

2006 ◽  
Vol 43 (10) ◽  
pp. 985-996 ◽  
Author(s):  
J -C Chai ◽  
J P Carter ◽  
S Hayashi
Keyword(s):  
Penetration Depth ◽  
Lateral Displacement ◽  
Fem Analysis ◽  
Field Measurements ◽  
Numerical Approach ◽  
Vacuum Pressure ◽  
Construction Time ◽  
Vacuum Consolidation ◽  
Prefabricated Vertical Drains ◽  
Prefabricated Vertical Drain

A method is proposed for determining the optimum penetration depth of prefabricated vertical drains (PVDs) in cases where vacuum consolidation is combined with the use of PVDs in a clayey deposit with two-way drainage. The advantages of combining vacuum pressure with embankment loading are discussed in terms of reducing preloading-induced lateral displacement of the subsoil, increasing the effective surcharge loading, and reducing construction time in the case of road construction. A vacuum consolidation project conducted in Saga, Japan, is described, and the results from a fully instrumented test section are presented and analyzed using a two-dimensional finite element approach. The numerical simulations compare well with the field measurements. The validated numerical approach is then used to examine the response of soft subsoil subjected to vacuum consolidation. The results confirm the usefulness of the proposed method for determining the optimum penetration depth of PVDs and the advantages of combining vacuum pressure with embankment loading.Key words: vacuum consolidation, preloading, prefabricated vertical drain, FEM analysis, embankment.

Prediction of impending failure of embankments on soft ground

2003 ◽  
Vol 40 (1) ◽  
pp. 209-220 ◽  
Author(s):  
Gavan Hunter ◽  
Robin Fell
Keyword(s):  
Pore Pressure ◽  
Factor Of Safety ◽  
Ground Deformation ◽  
Lateral Displacement ◽  
Deformation Behaviour ◽  
Vertical Displacement ◽  
Pressure Response ◽  
Excess Pore Pressure ◽  
Soft Ground ◽  
Pore Pressure Response

The deformation behaviour and excess pore pressure response of 13 well-monitored embankments on soft ground that were constructed to failure have been analyzed. The analysis shows that by monitoring lateral displacement at the toe of the embankment and vertical displacement at the toe and about 5 m beyond the toe, the onset of impending failure of embankments on soft ground can be detected while the slope is at about 70–90% of the failure height. This equates to an actual factor of safety of around 1.25. Monitoring of borehole inclinometers at the toe of the embankment, cracking of the embankment, and the pore pressure response and deformation during pauses in construction can provide useful additional data for detection of an impending failure.Key words: embankment on soft ground, deformation, pore pressure, failure, factor of safety.

scholarly journals STUDI PARAMETRIK JARAK PENGARUH PENURUNAN DAN PERGERAKAN LATERAL AKIBAT VACUUM PRE-LOADING PADA DAMAGE AREA SEKITAR

2020 ◽  
Vol 3 (4) ◽  
pp. 1091
Author(s):  
Mario Oktavianus Lay ◽  
Inda Sumarli ◽  
Ali Iskandar
Keyword(s):  
Lateral Displacement ◽  
Distance Effect ◽  
Soil Improvement ◽  
Deformation Analysis ◽  
Finite Element Program ◽  
Damage Area ◽  
Dimensional Finite Element ◽  
Element Program ◽  
Surcharge Load ◽  
New Material

 ABSTRACTSoil-fill is type of soil with low bearing capacity, therefore it’s need soil improvement to resolve the settlement. Soil improvement divided into 2 categories, namely methods that use new material and reinforcement. Commonly used method is PVD combined with vacuum pre-loading. Pre-loading is an application to increase surcharge load which aims to reduce the primary settlement occurs. Pre-loading not only causes settlement, but also cause lateral displacement which cause damage to the outside area around the improvement area. Thus, an analysis of distance effect between the improvement boundary and outside of improvement area in needed to prevent damage to utility around the site. Deformation analysis will be assisted by 2-Dimensional finite element program. Width of the improvement area is 80 meters with a depth of PVD is 14.5 meters to verify parameters. With the parameters that have been verified, an analysis is carried out on PVD with depth of 5m to 30m to determined distance effect of settlement and lateral displacement from boundary of the improvement area to until the value of the settlement and lateral displacement reaches <2cm. Result of studies on general is to find distance effect caused by vacuum pre-loading in areas outside the improvement boundary.ABSTRAKTanah hasil urugan merupakan jenis tanah lunak dengan daya dukung yang rendah, sehingga terjadi penurunan konsolidasi dan membutuhkan perbaikan. Perbaikan tanah dibagi menjadi 2 kategori, yaitu metode yang menggunakan material baru dan menggunakan pemanfaatan perkuatan. Metode yang umum digunakan adalah PVD yang dikombinasikan dengan vacuum pre-loading. Pre-loading adalah aplikasi penambahan beban surcharge yang bertujuan agar terjadinya penurunan primer. Pre-loading tidak hanya menyebabkan penurunan, tetapi juga menyebabkan terjadinya perpindahan secara lateral kearah luar yang dapat menyebabkan kerusakan pada area luar disekitar daerah perbaikan. Sehingga, dibutuhkan analisis jarak pengaruh antara batas lahan perbaikan dengan daerah luar perbaikan, untuk mencegah kerusakan pada struktur atau utilitas disekitar lokasi perbaiki. Analisis deformasi menggunakan program elemen hingga 2D. Lebar area perbaikan 80 meter dengan kedalaman PVD 14.5 meter untuk melakukan verifikasi parameter. Dengan parameter yang telah diverifikasi, dilakukan analisis pada PVD dengan kedalaman 5m hingga 30m untuk mengetahui jarak pengaruh penurunan dan pergerakan lateral dari batas lahan perbaikan hingga nilai penurunan dan pergerakan lateral <2 cm. Hasil studi secara umum menunjukkan seberapa besar jarak pengaruh yang diakibatkan oleh vacuum pre-loading pada daerah diluar batas perbaikan.

scholarly journals Estimation of Influence Scope of Lateral Displacement of Soft Ground under Vacuum Pressure with PVD

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jingyun Liu ◽  
Hongtao Fu ◽  
Jun Wang ◽  
Yuanqiang Cai ◽  
Xiuqing Hu
Keyword(s):  
Clayey Soil ◽  
Lateral Displacement ◽  
Soft Soil ◽  
Ground Surface ◽  
Vacuum Pressure ◽  
Vacuum Preloading ◽  
Treated Area ◽  
Prefabricated Vertical Drain ◽  
Soil Foundation ◽  
Soft Soil Foundation

The application of vacuum pressure to a treated area not only induces vertical settlement and inward lateral displacement but also causes the formation of tension cracks near the ground surface. In general, the strain method is applied to calculate the lateral displacement at the boundary of a treated area; however, the influence scope of lateral displacement has not yet been presented. Based on the in situ data of soft clayey soil foundation treated by vacuum consolidation, lateral displacement was estimated in the influence scope in this study. To calculate the influence scope of lateral displacement induced by vacuum pressure, the ratio of the lateral displacement within the influence scope to the ground surface settlement under the centre of the treated area is defined as the maximum value of the lateral displacement (ELD) within the influence scope. This paper proposes a direct relationship between ELD and the distance from the treated area boundary (Lx), considering the length of the prefabricated vertical drain. In addition, the FEA (finite-element analysis) is used to simulate the process of vacuum preloading to reinforce soft soil foundation. The influence scope simulated is almost close to the calculated value Lx. Accordingly, the safety distance between the boundary of the treated area and the surrounding building can be estimated when the soft soil foundation is consolidated by using a vacuum preloading method.

scholarly journals Numerical modelling of soft soil stabilized by vertical drains, combining surcharge and vacuum preloading for a storage yard

2007 ◽  
Vol 44 (3) ◽  
pp. 326-342 ◽  
Author(s):  
Cholachat Rujikiatkamjorn ◽  
Buddhima Indraratna ◽  
Jian Chu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Plane Strain ◽  
Water Pressure ◽  
Vacuum Pressure ◽  
Element Analysis ◽  
Prefabricated Vertical Drains ◽  
Vertical Drains ◽  
Modified Cam Clay ◽  
Surcharge Load

This paper presents a finite element analysis of a case study of a combined vacuum and surcharge load through prefabricated vertical drains (PVD) at a storage yard at Port of Tianjin, China. The top 15 m of soil at this site was very soft to soft and needed to be improved using preloading surcharges of more than 140 kPa. To avoid any stability problems associated with a high surcharge embankment, 80 kPa vacuum pressure combined with fill surcharge was applied (40 and 58 kPa for sections I and II, respectively). A plane strain analysis was performed using equivalent permeability and transformed unit-cell geometry. The converted (equivalent) parameters were incorporated in the finite element code ABAQUS, using the modified Cam-Clay theory. The performance of a trial embankment at the site of the storage yard is predicted on the basis of a constant vacuum pressure applied on the soil surface and distributed along the length of the drain. The predictions of settlement, pore-water pressure, and lateral displacement were compared with the available field data, and an acceptable agreement was found based on this numerical approach. The combination of vacuum and surcharge load can effectively shorten the preloading period, reduce the height of the embankment, and counterbalance excessive lateral displacements.Key words: consolidation, finite element analysis, plane strain method, soil improvement, vertical drains.

The Inclination of Bridge Pier due to Neighboring Embankment Construction and its Rectification Technique

2013 ◽  
Vol 353-356 ◽  
pp. 79-83
Author(s):  
Ming Lei Shi ◽  
Hao Zhang ◽  
Rui Kun Zhang
Keyword(s):  
Lateral Displacement ◽  
Soft Soil ◽  
Dynamic Test ◽  
Road Construction ◽  
Bridge Piers ◽  
Site Monitoring ◽  
Surcharge Load ◽  
Standard Set ◽  
Bridge Bearings ◽  
Soil Area

In case of highway road construction often beneath existing overpass project, the filling of neighboring embankment may cause lateral displacement of bridge piers, which seriously threaten the safety of bridge. One case history, for inclination disease of overpass bridge piers in soft soil area, was presented. Aiming at the deformation of piers caused by the neighboring embankment construction, the displacement feature of bridge bearings were tracked and measured by site monitoring, and the damaged position of piles were clarified with low strain dynamic test. For these geological traits, the reasons of the inclination were analyzed. And the rectification method of applying surcharge load for smaller deviation (50mm) and the rectification method of pushing combined traction for serious deviation (>50mm) were respectively put forward on the basis of the lateral displacement statistics of bearings and the analytical standard set by Bozozuk. Site observation indicates these rectification methods can achieve the desired results.

Sign in / Sign up

Export Citation Format

Share Document