Jason S. Lueke

Application of simulation in trenchless renewal of underground urban infrastructure

Pipe bursting is a type of trenchless technology that enables the construction, rehabilitation, or replacement of underground urban infrastructure with minimal disruption to surface activity. This construction process facilitates the installation of sewer pipes and gas mains of similar or larger diameters at the same location as existing lines. The upsizing capability is particularly relevant in situations where greater flow capacities are required due to increased urbanization. The paper presents an application of a simulation platform developed at the University of Alberta called Simphony, used to create a special purpose simulation application of the pipe bursting process. Results obtained from this model can assist owners, engineers, contractors, and equipment manufacturers in designing and planning pipe bursting projects.

Subsurface Ground Movements Associated with Trenchless Pipe Replacement Methods

As we enter the new millenium, our nation is facing a crisis resulting from underground infrastructure that are functioning far beyond any reasonably anticipated design life and require renewal to mitigate deterioration. Maintaining this large network of underground sewer, water, and gas pipelines is difficult and costly. The problem is compounded by the significant impacts that a major repair or rehabilitation project can have on the daily life, traffic, and commerce of the area served by and along the pipeline in question. Trenchless pipe replacement, or pipe bursting, provides a trenchless alternative for the renewal of underground infrastructure. The process includes various static, hydraulic, and pneumatic methods of breaking an existing pipe and simultaneously installing, by pulling or pushing, a new pipe of equal or larger diameter. One of the greatest challenges facing acceptance of this renewal option is the issue of its effects on adjacent buried infrastructure. This paper describes a unique approach for monitoring subsurface ground movements during the pipe bursting process to assist planners and contractors in evaluating the risk of potential damage to surrounding structures. Initial field testing of this procedure on the Millstone Sanitary Trunk Sewer project in the City of Nanaimo, British Columbia is described. It is anticipated that adoption of this trenchless method of urban renewal will increase, as more techniques are developed to quantify the risks associated with soil movements. l Graduate Research Assistant, Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, Canada T6G 2G7; tel. (780) 492-8966, fax (780) 492-0249 2 Assistant Professor, Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, Canada T6G 2G7; tel (780) 492-5110, fax (780) 492-0249

Validation of photogrammetric monitoring for trenchless construction applications

A primary concern of owners specifying trenchless installation and rehabilitation methods are surface movements during construction. Surface heave or settlement can occur as a result of contractor methodology, design, or geotechnical conditions. Performing quality assurance during and after construction provides owners with an understanding of what surface movements have occurred and if remedial action may be required. Traditional methods utilized to measure ground surface movements include surveying triangulation, geometric leveling, and global positioning system (GPS) surveying. This paper presents a procedure to utilize photogrammetry in the measuring of ground movements and examines its precision and accuracy in simulated field conditions. Utilizing consumer-grade digital single lens reflex (SLR) cameras, photogrammetry does not require highly trained personnel, takes less time, and costs less money than traditional methods. Accuracy is determined by comparing measurements taken with photogrammetry to those taken with traditional rod and level. The results are compiled and analyzed to determine the accuracy and precision of photogrammetry in measuring ground movements.

Analytical Decision Analysis for Construction Methodology Selection for a Water Transmission Main River Crossing

AbstractThe decisions made during the preproject planning and design stages are very crucial for infrastructure and underground projects due to the inherent risks and uncertainties in such projects. In the selection of a crossing method, the owner has to consider various factors, including cost, environmental impact, serviceability and maintenance, constructability, and schedule. Unfortunately, this decision is complex due to the numerous variables that need to be considered. When choosing a crossing methodology, the project manager must balance the likely capital cost of the project with the risks inherent in the chosen construction method. Ideally, a project manager would investigate numerous alternatives to fully explore the merits of various construction methods, including the level of risk, before making the final decision. This paper presents the results of an actual project workshop with the objective of selecting the most optimum construction method for the construction of a water transmission mai...

NUMERICAL ANALYSIS OF SUBMERGED SOIL BEHAVIOR IN PIPELINE INSTALLATIONS CROSSING RIVERS

The paper investigates the pattern of soil stress around a pipeline installed under the river using a non-linear three-dimensional finite element method (FEM). This study compares von Mises soil stresses occurring in native soil adjacent to river crossing pipeline between traditional open trench (OT) and horizontal directional drilling (HDD) pipe installation methods. The MohrCoulomb theory is utilized to describe soil behavior in the finite element models. The entire model is assumed to be elasto-plastic. The whole research considers saturated native soil in one month after construction. Additionally, design parameters (i.e. depth of cover and annular space) in HDD method are examined for understanding their influence on soil stress occurring around original soil. The paper investigates how critical design parameters (i.e. density and diameter) in the annular space affect the pattern of maximum von Mises soil stresses occurring in native soil adjacent to pipeline installed under the river. Finally this study found that when the OT method is used for pipeline crossing under the river, stress occurring in the soil cover is greater than when the HDD method is used. In addition, the diameter of the annular space in HDD method could impact on total soil stress occurring in the soil overburden.

Prediction of surface heave associated with horizontal drilling using neural networks

This paper presents the implementation of an artificial neural network to predict surface heave resulting from shallow subsurface utility installations conducted with horizontal directional drilling. Data gathered from a full factorial field experimentation examining the effects of drilling techniques is utilized in the network development, with the attempt to understand the relationship between construction techniques and resulting surface heave. The developed model is compared to a multivariate linear regression analysis conducted on the raw data, and a sensitivity analysis utilizing the trained network connection weights is conducted to determine which factor has the greatest effect on surface heave development. Further examination of the behavior of the system is provided through a trend analysis which studied the effect of each drilling factor on the predicted surface heave. The results indicate that a neural network would adequately model the relationship between drilling techniques and the resulting surface heave.