Terms & Conditions

Data Security

We are committed to ensuring that your information is secure. In order to prevent unauthorised access or disclosure we have put in place suitable physical, electronic and managerial procedures to safeguard and secure the information we collect.

All data is stored in secure electronic systems accessible only to Oasys staff with both valid network login credentials and specific authorisation to access the system.  Our systems further limit data access by role to ensure data is available only to those who have a specific need to see it.

If at any point you suspect or receive a suspicious communication from someone suggesting they work for Oasys or a website claiming to be affiliated with Oasys, please forward the communication to us or report the incident by email to [email protected] or in writing to Oasys, 8 Fitzroy Street, London, UK, W1T 4BJ as soon as possible.

Data Security Notice Updated 27th February 2020

top ]


 

Website Terms and Conditions

The contents of this web site are protected by copyright and other intellectual property rights under international conventions. No copying of any words, images, graphic representations or other information contained in this web site is permitted without the prior written permission of the webmaster for this site.

Oasys accepts no responsibility for the content of any external site that links to or from this site.

top ]

 


 

Software Licensing Terms

Terms and Conditions of Purchase

The full conditions of purchase and maintenance for all Oasys desktop software are set out in the Oasys Software Licence and Support Agreement.

The full conditions of purchase and maintenance for Oasys Gofer and Oasys Giraphe are set out in the Gofer SaaS Agreement  and the Giraphe SaaS agreement.

All prices are subject to TAX at the current rate.

Prices and specifications are subject to change without notice – please ask for a written quotation.

Although every care has been taken to ensure the accuracy of all information contained herein, the contents do not form or constitute a representation, warranty, or part of any contract.

Superseded Versions of Terms and Conditions

Oasys keeps copies of all superseded versions of its terms and conditions.

Maintenance & Support Services

Support and maintenance is included with all subscription licences for their full duration.

Annual maintenance contracts are available for software under a perpetual licence, prices are based on a percentage of the most recent list price.

This service includes:

 

top ]

 


 

Cookies Policies

View available cookies policies below:

 

top ]

 

Estimate the Impact of Scouring on the Lateral Load Capacity of Piles

Software Used on this Project

Project Overview

Bridges located in hilly terrains and resting on pile foundations are often subjected to significant scouring on account of fast flowing river water. Such phenomenon can be detrimental as they lower the lateral carrying capacity of the piles due to the removal of soil support. Based on the permissible deflection of the pile at its cut-off level, this article reports the estimation of lateral load capacity of a single free-headed pile embedded in stratified deposit.

Oasys Alp has been used to carry out the analysis. Extreme scouring depths (in the tune of 5-7 m has been accounted) portray vivid degradation of the lateral load capacity of pile (in the tune of 20 – 40%).

How Oasys proved invaluable

Non Linear P-Y Analysis

Oasys Alp was used to carry out the lateral load capacity analysis of a single vertical pile embedded in stratified deposit.

The software considers the presence of water table, and also determines the flexural response of the pile through automatic load increment to reach the failure load in progressive steps. Alp also considers the passive resistance of the soil and indicates when the passive resistance of the soil is exceeded. To carry out the analysis, the pile has been discretized into nodes with a uniform spacing of 0.5 m. Required refinements were made in the intersection with the water table and soil strata interface. A typical Alp output is shown below:

Results and Discussion
Load-Deformation Response and Lateral Load Capacity of Pile

The feature of automatic load increment available in Oasys Alp has been used to estimate the lateral load capacity of the pile. For the present problem, the load acting at the pile head has been set to a reasonable value (e.g. 250 kN) and the number of increments to reach the load has been provided (13 increments). This enabled the researchers to obtain the cumulative flexural response of the pile with the load increments. The following figure shows a typical load increment procedure in terms of the deflection response of the pile (1000 mm diameter):

From the above observation, considering the deflection criterion as 10% of the pile diameter at cut-off level, the lateral load capacity of the pile has been estimated. The following figure depicts the lateral load capacity as estimated from the Oasys Alp software. It can be observed from the plots that the load-deflection curves reveal nonlinear behaviour for higher diameter piles.

The researchers in IIT go on to show the P-Y curves that are generated at the top and bottom of each soil layer. It is noticeable that the clayey layers (which are more plastic than the sandy layers) show more non-linear behaviour, and reach the plastic limit condition. The sandy layers show mostly bilinear behaviour and, as indicated in the figure, need to be subjected to large load values to reach their ultimate state. Hence, the linear/nonlinear flexural behaviour of the pile will be governed by the thickness and location of the clayey or sandy stratum.

Conclusions

Based on the study, the following important conclusions can be stated:

  • An increase in the diameter of the embedded piles results in the increase in the maximums of its flexural responses
  • The length of fixity is not significantly affected by the change in the pile diameter. This is because the length of fixity is not governed alone by the flexural rigidity of the pile, but by the relative flexural rigidity of the pile and the surrounding soil. This feature is portrayed by the software Oasys Alp and hence, length of fixity remains primarily invariant with the change in the pile diameter
  • Increase in the scouring significantly decreases the lateral load capacity of the soil (in the tune of 20 – 40%). The degradation is more prominent when scouring takes place in the softer soil stratum
  • The presence of water table, thus reducing the effective unit weight of the submerged soil, also decreases the lateral load capacity of the embedded pile
  • P-Y curves generated reveal that the clay layers show prominence in nonlinear behavior and reaches the plastic limit under failure load condition, while sandy layers, commonly behaving as elastic, show at most bilinear behavior and indicates that this kind of soil require high loads to reach into their plastic limit

 

Credits:

A. Dey, Assistant Professor, IIT Guwahati

A. K. Yadav, Resident Engineer, Jayprakash Associates

What is your query?

  • This field is for validation purposes and should be left unchanged.

Newsletter Sign up

Please fill out your details below to receive the latest oasys news.

  • This field is for validation purposes and should be left unchanged.