Bearing Capacity Characteristics of Lacustrine Soft Clay Hard Shell Layer Foundation

2013 ◽  
Vol 347-350 ◽  
pp. 1203-1206
Author(s):  
Jia Jia Zheng ◽  
Li Jian Wu ◽  
Run Hua Guo
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Shear Failure ◽  
Soft Soil ◽  
Soft Clay ◽  
Soil Layer ◽  
Shell Layer ◽  
Soft Foundation ◽  
Hard Shell ◽  
Punching Failure

In order to provide a theoretical basis for the use of lacustrine soft clay hard shell layer, the first thing to do is understanding its bearing capacity characteristics. Based on the project of Nan-Mao section in Hunan provincial highway S204, combining with bearing capacity test, the bearing capacity characteristics and failure mode of hard shell foundation was comprehensively analyzed. From the field bearing capacity test, it is found that the PS curve of hard shell layer has obvious changes from elastic to plastic, while the PS curve of soft soil layer under hard shell layer just has elastoplastic stage from the beginning, and the failure mode of foundation mainly are punching failure and general shear failure. So for the quality control of lacustrine hard shell soft foundation mainly includes two aspects: the deformation and overall stability.

Model Test of Bearing Capacity of WasteTire Assembly Foundation on Soft Soil Layer

2021 ◽  
Vol 69 (7) ◽  
pp. 263-269
Author(s):  
Me ti ◽  
Tri Harianto ◽  
Abdul Rachman Djamaluddin ◽  
Achmad Bakri Muhiddin
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Soft Soil ◽  
Soil Layer

Effect of a Strong Middle Layer on Spudcan Penetration

2014 ◽  
Author(s):  
Wen Gao ◽  
Tom Harrup ◽  
Yuxia Hu ◽  
David White
Keyword(s):  
Bearing Capacity ◽  
Layer Thickness ◽  
Soft Clay ◽  
Soil Layer ◽  
Strength Ratio ◽  
Top Soil ◽  
Flow Mechanisms ◽  
Soil Flow ◽  
Jack Up ◽  
Peak Resistance

The rapid penetration of one or more of the foundations of a mobile jack-up rig into the seabed is an ongoing major problem in the offshore industry, with the potential to cause major damage to the structure and endangering any personnel on board. A recent example is the jack-up drilling rig Perro Negro 6 incident happened near the mouth of the Congo river in July 2013 with one of the rig’s crew of 103 reported missing and six others injured. This uncontrollable displacement is due to a form of failure known as punch through failure and commonly occurs on stratified seabed profiles. It has been reported that unexpected punch-through accidents have resulted in both rig damage and lost drilling time at a rate of 1 incident per annum with consequential costs estimated at between US$1 and US$10 million [1]. This paper presents the bearing capacity profiles and associated soil flow mechanisms of a common spudcan foundation penetrating into a three layer soft-stiff-soft clay soil through the use of large deformation finite element (LDFE) analysis. The Remeshing and Interpolation with Small Strain (RITSS) [2, 3] technique was implemented in the software package AFENA [4] to conduct the LDFE analysis. Both soil layer thickness and soil layer strength ratios were varied to study their effect on the spudcan penetration responses. The LDFE results of spudcan penetration into the soft-stiff-soft clay soils were calibrated by existing centrifuge test data. A parametric study was then conducted to study the bearing capacity responses and soil flow mechanisms during spudcan large penetrations by varying the soil layer strength ratio and relative layer thickness to the diameter of spudcan. It was found that there were three types of bearing responses during continuous penetration of spudcan: (a) when the top soft layer is relatively thin, the spudcan bearing response was similar to that of two layer soils with stiff over soft clays; (b) when the top soil layer thickness is medium, a peak resistance is observed when spudcan penetrates into the middle stiff layer followed by reduction; (c) when the soil layer is thick, the peak resistance occurs when spudcan gets into the bottom soft soil layer. The critical thickness of top soil layer is a function of soil strength ratio and middle stiff soil layer thickness. The bearing response types were also corresponding to the soil cavity formations during spudcan initial penetration.

Predicting the overall horizontal bearing capacity of jack-up rigs using deck–foundation–soil-coupled model

2020 ◽  
pp. 147509022092590
Author(s):  
Qilin Yin ◽  
Jinjin Zhai ◽  
Sheng Dong
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Double Layer ◽  
Soft Clay ◽  
Coupled Model ◽  
Single Layer ◽  
Horizontal Load ◽  
Foundation Soil ◽  
Failure Envelopes ◽  
Jack Up

The overall bearing capacity of a jack-up rig under horizontal load is conducted using finite element models that consider the deck–foundation–soil interaction. In these models, the simplified horizontal load acts on the deck and increases until the platform loses its stability. The effects of the self-weight of the platform W and load direction α on the ultimate horizontal bearing capacity Hult are investigated, and W- Hult failure envelopes under different α conditions are obtained. Two typical seabed types, including the double-layer seabed of sand overlying soft clay and the single-layer seabed of sand, are considered. The results show that a critical self-weight Wcritical exists in the double-layer seabed. Based on Wcritical, the failure of the platform presents two different modes. When W <  Wcritical, the windward leg is pulled up, and Hult increases with the increase in W. When W >  Wcritical, the failure mode is the leeward leg or legs puncturing the bearing sand layer, and Hult decreases with the increase in W. In the single-layer seabed, the failure mode is the windward leg being pulled up, and Hult increases with the increase in W throughout the whole range. The W- Hult envelopes in these two types of seabeds are basically the same when W <  Wcritical.

Model Test Research of Surcharge Contribution to Ground Bearing Capacity

2013 ◽  
Vol 353-356 ◽  
pp. 815-818
Author(s):  
Le Yi Chen
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Model Test ◽  
Shear Failure ◽  
Theoretical Solution ◽  
Capacity Factor ◽  
Ground Failure ◽  
Capacity Model ◽  
Capacity Calculation ◽  
Bearing Capacity Factor

To investigate the influence of surcharge on bearing capacity, model tests were performed. In the tests, 5 kPa and 10 kPa surcharge was applied on silt respectively. The bearing capacity factor Nq is smaller than theoretical solution, and is only of 60.3% and 80.5% of theoretical solution. Model test show that the ground failure mode is not general shear failure mode in condition of ground under surcharge. In bearing capacity calculation, if bearing capacity factor theoretical solution which is from general shear failure mode is applied, the result will be overestimate.

scholarly journals Pemodelan Penurunan Pondasi Struktur Bangunan di Tanah Lunak Kota Banjarmasin Menggunakan Ansys

2021 ◽  
Vol 5 (2) ◽  
pp. 117-130
Author(s):  
Darmansyah Tjitradi ◽  
Eliatun Eliatun ◽  
Oktafianus Steven Tjitradi
Keyword(s):  
Bearing Capacity ◽  
Structural Damage ◽  
Soft Soil ◽  
Soft Clay ◽  
Structural Models ◽  
Differential Settlement ◽  
Foundation Settlement ◽  
Structural Elements ◽  
Ansys Software ◽  
Clay Type

The soil in Banjarmasin City is of soft clay type having a very low bearing capacity. Hence, it is normal for buildings in this area to have gelam wooden piles as part of the foundation. Foundations based on gelam wooden piles rely on friction which results in the building experiencing differential settlement, tilt, and cracks on the structural elements. This foundation settlement will be modeled using ANSYS software involving fifteen building structural models with brick walls under loads according to SNI 1727:2013 and due to settlement at the support. The modeling aims at understanding the effects of using tie beams on the pattern of structural damage in buildings that experience differential settlement on soft soil. Hasil penelitian menunjukkan bahwa penggunaan tie beam pada pondasi pada tanah lunak berpengaruh terhadap pola kerusakan. Pada tanah keras, ini tidak membawa efek seperti itu tetapi sebaliknya, itu meningkatkan tingkat ketidaktentuan statis struktur. Dalam kasus portal bentang tunggal, pola retakan menyerupai huruf "V" terbalik jika penurunan terjadi pada tumpuan samping. Di portal bentang ganda, di sisi lain, pola retakan dinding bata menyerupai huruf "V" jika penurunan terjadi pada penyangga samping, dan "V" terbalik jika terjadi di antara penyangga.

scholarly journals Bearing Capacity of Floating Foundations Used PVC (Poly Vinyl Chloride) on Soft Soil With The Scale Model in the Field

2018 ◽  
Vol 7 (2.5) ◽  
pp. 84 ◽  
Author(s):  
Susy Srihandayani ◽  
Desi Putri ◽  
Nuning Kurniasih ◽  
Lusi Dwi Putri
Keyword(s):  
Theoretical Analysis ◽  
Bearing Capacity ◽  
Clay Soil ◽  
Soft Soil ◽  
Soft Clay ◽  
Maximum Load ◽  
Scale Model ◽  
Degradation Model ◽  
Poly Vinyl Chloride ◽  
Foundation Model

A soft clay soil has a low support energy, so it needs to be planned a foundation form that able to improve soil bearing capacity and estimate a maximum load that can be supported by that soil. Planning a float foundation is one of the solutions to overcome that problem. The behavior of burden degradation at float foundation which obtained from encumbering of axial introduced here. Proposed analysis based on classical theory and examination of foundation at the field. Float foundation models with different amount and dimension. At the field, a pipe which one of its ends closed tightly came into soft clay soil and then encumbered step by step. Giving an axial burden and degradation model area and noted. Boundary capacities in each foundation model estimated from the curve of load-displacement yielded of the test. From the result of theoretical analysis at a single float foundation got a proportionate result with the field result but after giving additional pile/pipe with larger one's cap got the theoretical result of bearing capacity bigger than the field result. The efficiency value of the comparison of bearing capacities theoretically that using five classic methods got more than 100%, and after giving additional pipe, the efficiency value near to 100%.  

The Plate Body Stabilization Technology of Soft Soil Subgrade in Caofeidian Area

2014 ◽  
Vol 501-504 ◽  
pp. 150-154
Author(s):  
Dong Guo Li ◽  
Jian Ping Chen ◽  
Yong Qiang Zhang
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Soft Soil ◽  
Load Test ◽  
Construction Technology ◽  
Static Load Test ◽  
Treatment Methods ◽  
Soft Foundation

The applicability of the plate body stabilization technology was determined basing on the different treatment methods on soft foundation in Caofeidian areas. It discussed the construction technology and the main points of construction furtherly on the plate body stabilization technology. The soft foundation bearing capacity reached 200kpa and the settlement amount was less than 16mm through static load test after dealing with the soft foundation. The results meet the specifications and project requirements.

scholarly journals Behavior of Stone Column improved Clay soil under static loading-A numerical exploration

2020 ◽  
Vol 9 (9) ◽  
pp. 440-445
Keyword(s):  
Bearing Capacity ◽  
Soil Stabilization ◽  
Clay Soil ◽  
Soft Soil ◽  
Soft Clay ◽  
Cost Effective ◽  
Element Model ◽  
Vital Role ◽  
Stone Column ◽  
Cost Effective Method

Problematic soil which cause extra problems from engineering point of views which result in its composition or environmental conditions change. The weak subsoil deposits like soft clay pose the low bearing capacity and more settlements over long periods of time. The stone column technique is better, economical and cost-effective method of soft soil stabilization. They are used to support embankments, large raft foundations and isolated footings. Numerous researchers have just completed various vertical stacking probes stone column balanced out clay bed and have discovered that expands bearing capacity of delicate clay, diminishes displacement and changes the conduct of burden settlement. In the current study, a 2D finite element model is completed to evalute how the delicate clay soil balanced out by stone column are affected by the vertical burdens. Stone column were intended for examinations with fluctuating in their angle proportions (change in estimations of length, L and breadth, D) of stone column. The effect of floating stone column and end bearing stone segment on delicate clay is in like manner controlled by using various L/D ratios. Besides, the present outcomes express how the heap conveying limit of stone column is differed by changing in the angle proportions of the stone column. Likewise ends were drawn that bulging impact of stone column plays a vital role in conveying vertical burden.

Stability Analysis of the Semi-Circular Guiding Dike

2014 ◽  
Vol 638-640 ◽  
pp. 1270-1273
Author(s):  
Zhong Xiao ◽  
Yuan Zhan Wang ◽  
Ke Li Sun ◽  
Li Qiang Sun
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Yield Criterion ◽  
Soft Clay ◽  
Wave Load ◽  
Obvious Effect ◽  
Cyclic Shear ◽  
Finite Element Software ◽  
Soft Foundation ◽  
Before And After

A quasi static finite element method for assessing cyclic bearing capacity of semi-circular guiding dike on natural or reinforced soft clay foundation is developed by combining the concept of cyclic shear strength with D-P yield criterion. Then the proposed method is numerically implemented in the framework of the large universal finite element software. Combining with a practical engineering, the stability of semi-circular guiding dike before and after foundation reinforcement is analyzed. The results showed that the foundation bearing capacity decreases obviously when cyclic weakening effect of soft foundation was considered, so cyclic weakening effect of soft foundation under cyclic wave load should be considered in practical design. Moreover, foundation reinforcement has an obvious effect to increase foundation bearing capacity.

scholarly journals Analisis Alternatif Perbaikan Tanah Lunak dan Sangat Lunak pada Jalan Tol

2020 ◽  
Vol 3 (4) ◽  
pp. 1137
Author(s):  
Christian Eka Putra ◽  
Chaidir Anwar Makarim
Keyword(s):  
Bearing Capacity ◽  
Soft Soil ◽  
Soft Clay ◽  
Soil Improvement ◽  
High Water Content ◽  
Vacuum Preloading ◽  
Consolidation Process ◽  
Toll Road ◽  
Vertical Drain ◽  
Prefabricated Vertical Drain

The existence of soft soil is one of the problems in the field of construction. Soft soil is soil that has high water content and low carrying capacity. In the case of this toll road, soil investigation at the site shows that the subgrade in the toll road planning is soft clay soil to a depth of 32 meters so that soil improvement is needed. High landfill built on soft subgrade without reinforcement will experience landslides. So it is necessary to strengthen the landfill and repair the subgrade to prevent road slides. The soil improvement methods in use are vacuum preloading and Prefabricated Vertical Drain with the vacuum functioning as an additional load. In addition to accelerating the consolidation process, the vacuum can also reduce the height of the embankment needed to achieve the desired planned road elevation. Strengthening with geotextile is also carried out on the landfill with a height of 5.94 meters so that there is no landslide on the fill. Using soil improvement methods such as vacuum preloading and prefabricated vertical drain will increase the bearing capacity of the soil so that differences in bearing capacity occur before and after repair. AbstrakKeberadaan tanah lunak menjadi salah satu masalah dalam bidang konstruksi. Tanah lunak adalah tanah yang memiliki kadar air yang tinggi dan daya dukung yang rendah. Pada kasus jalan tol ini, penyelidikan tanah di lokasi menunjukan bahwa tanah dasar pada perencanaan jalan tol merupakan tanah lempung lunak hingga kedalaman 32 meter sehingga dibutuhkan perbaikan tanah dasar. Timbunan tinggi yang dibangun di atas tanah dasar lunak tanpa perkuatan akan mengalami kelongsoran. Sehingga diperlukan perkuatan timbunan dan perbaikan tanah dasar untuk mencegah kelongsoran jalan. Metode perbaikan tanah yang digunakan adalah vacuum preloading dan Prefabricated Vertical Drain dengan vacuum berfungsi sebagai beban tambahan. Selain mempercepat proses penurunan, vacuum juga dapat mengurangi tinggi timbunan yang dibutuhkan untuk mencapai elevasi jalan rencana yang diinginkan. Perkuatan dengan geotextile juga dilakukan pada timbunan dengan tinggi yang mencapai 5.94 meter supaya tidak terjadi kelongsoran pada timbunan tersebut. Dengan menggunakan metode perbaikan tanah berupa vacuum preloading dan prefabricated vertical drain akan meningkatkan daya dukung tanah sehingga akan diketahui perbedaan daya dukung yang terjadi sebelum dan sesudah diperbaiki.

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