Pipe Ramming Research Articles

Compressed air parameters for spoil removal in casing pipe ramming in soil

Compressed air parameters for spoil removal in casing pipe ramming in soil

Lubrication performance of pipejacking in soft alluvial deposits

Pipejacking technologies has been extensively chosen by many mega cities worldwide to construct their sewer pipelines. Lubrication has been deemed to be the key factor in manipulating the performance of pipejacking works. Inadequate lubrication during pipejacking can lead exaggerated jacking force causing damages to the jacked pipe string and adjoining properties. Due to limited studies, a consensus has not yet reached. This study gives an access of evaluating the lubrication performance via the reduction in the frictional coefficient μ and investigates the impacts of injection type, soil and lubrication natures, and misalignment on the lubrication performance for a pipejacking project in alluvial soil deposits. The effect of misalignment, while ramming through the 8–21 m section of gravel at Drive C, gears up the frictional stress τld to 12.5 kPa (compared to 0.4 kPa of the 2–8 m section of the same gravel) and reduces the reduction to 71%. While traversing through the 24–31 m section of clayey gravel at Drive D, the occasional gravel not being long enough to develop lower face resistance leads the misleading reduction of 60%. These factors have greater influences on the lubrication performance than the injection type. The presented results would be helpful in managing the lubrication performance while pipe ramming for upcoming pipejacking project.

Analysis on mechanical influencing factors of fatigue behavior for the packer on pipe ram in snubbing unit

In snubbing service, the ram blowout preventer (BOP) is switched frequently, and the stress condition of the packer is very complicated. Cracks, rubber drop, and other fatigue failures often occur. The load characteristic was firstly analyzed in this paper based on the stress condition of packer in snubbing service. The mechanical property of rubber commonly used for packer was tested, and the performance parameters were obtained. Based on the crack initiation approach, taking the rubber matrix as the research object, the effective stress, the maximum Green–Lagrange strain and strain energy density were selected as damage parameters. The distribution contour of three damage parameters of the rubber matrix of the packer under different stress conditions and speeds of lifting or lowering pipe were obtained using finite element method (FEM). The effect of different stress conditions and speeds of lifting or lowering pipe on the fatigue behavior for the rubber matrix was analyzed. The result shows that the value of three damage parameters is relatively high on the upper area of the rubber matrix, causing the first occurrence of fatigue in the upper part, which agrees well with the oilfield application. The speed of the pipe does not change the location of fatigue point and the value of damage parameters, so that it has little effect on the fatigue behavior of the packer's rubber matrix. Finally, based on Miner linear damage rule, a calculation method for the fatigue behavior of the packer is presented.

Designing Methodology for Identifying Different Types of Influx Entering in a Well Bore during Drilling and Study of Influx Behavior

Drillers frequently encounter kick in drilling operations. Kick refers to the unwanted entry of formation fluid into the well bore. Primary well control and secondary well control are used to control influx entry into a well during drilling operations. Primary well control refers to making the overbalance by the hydrostatic pressure exerted by drilling fluid on the formation pressure. Secondary well control refers to controlling the kick through the use of BOPs. BOPs consist of annular preventers, pipe ram, shear ram and blind ram. Reservoir fluid entering the well bore during drilling or tripping is called influx. Influx encountered in a well bore could be oil, water and gas or their mixture. Behavior of all the influxes is different. For example, if a gas influx is encountered, it percolates upwards in the annulus while if water it there it just mixes with the drilling fluid and causes a reduction in its density. The behavior of gas influx in open well and closed well condition is different and complex. In this paper, the behavior of different types of influxes encountered in a well bore has been thoroughly studied and a methodology for understanding the type of well influx that has entered the well bore has been designed. Keywords: Kick, influx behavior, influx identification, well control

ON SIGNIFICANCE OF FORCE IMPACT ON THE WORKING TOOL CUTTING INTO ROCK MASS BY PUNCTURE AND PIPE RAMMING METHODS

ON SIGNIFICANCE OF FORCE IMPACT ON THE WORKING TOOL CUTTING INTO ROCK MASS BY PUNCTURE AND PIPE RAMMING METHODS

The perspective of batch-wise removal of soil plug from pipes during trenchless installation

Modern approaches to construction of utility lines are reviewed. The hole-making technology of pipe driving can be improved by introduction of concurrent removal of soil plug by batches, which essentially enhances performance efficiency. The minimum air pressure required to separate batches from soil plug and to move it along a pipe is determined. The feasibility of cyclic destruction and removal of soil plug during pipe ramming is experimentally proved.

Real-Time Condition and Performance Monitoring of a Subsea Blowout Preventer Pipe Ram

Summary Presented here is a case study on the condition and performance monitoring (CPM) of a subsea blowout preventer (BOP) pipe ram. The proposed real-time CPM solution uses adaptive physics-based models that process sensor measurements at the point of origin (known as edge analytics). The adapted model coefficients are treated as a vector, the magnitude of which estimates the degree of health degradation and the phase of which identifies its source. The benefits of using an adaptive model-based approach over traditional machine-based learning and artificial-neural-networks solutions include zero algorithm-training times, broad applicability to BOPs, model modularity, and accurate health-degradation estimates. The proposed CPM methodology is validated on a BOP pipe ram using both operational and simulated data. A sensitivity study of the method to system uncertainty is also presented.

Influence of Pipe Ramming on Stress State of Surrounding Soil and Nearby Tunnel Lining

ANNOTATIONThis article proposes an approach to the prediction of stress state and assessing the strength of a circular tunnel lining and the surrounding rock mass under construction near the production used by the micro-tunneling technology of pipe ramming. The basis of this method is an analytical solution of the corresponding plane problem of elasticity theory.

Attenuation of Pipe Ramming-Induced Ground Vibrations

AbstractPipe ramming installations generally induce high levels of ground vibrations that may affect the structural integrity of nearby buildings and utilities. This paper investigates the ground vibrations associated with pipe ramming installations and develops reliable models for estimating the ground vibration levels in an effort to avoid the undesirable effects of the vibrations. The study presents field observations of ground vibrations in which an open-ended steel casing 1,070 mm in diameter and 37 m long was driven into granular soils using two pneumatic hammers of varying energy. The ground vibrations observed during the installation are presented as a function of magnitude of peak particle velocity, frequency content, and direction of propagation. Observations indicate that a wide range of amplitudes and frequencies is possible, ranging from 1 to 100 mm/s and 20 to 100 Hz, respectively, for the case of forward and laterally propagating vibrations. The forward-propagating vibrations were observed...

Real-time reliability evaluation methodology based on dynamic Bayesian networks: A case study of a subsea pipe ram BOP system

A novel real-time reliability evaluation methodology is proposed by combining root cause diagnosis phase based on Bayesian networks (BNs) and reliability evaluation phase based on dynamic BNs (DBNs). The root cause diagnosis phase exactly locates the root cause of a complex mechatronic system failure in real time to increase diagnostic coverage and is performed through backward analysis of BNs. The reliability evaluation phase calculates the real-time reliability of the entire system by forward inference of DBNs. The application of the proposed methodology is demonstrated using a case of a subsea pipe ram blowout preventer system. The value and the variation trend of real-time system reliability when the faults of components occur are studied; the importance degree sequence of components at different times is also determined using mutual information and belief variance.

Availability analysis of subsea blowout preventer using Markov model considering demand rate

Availabilities of subsea Blowout Preventers (BOP) in the Gulf of Mexico Outer Continental Shelf (GoM OCS) is investigated using a Markov method. An updated β factor model by SINTEF is used for common-cause failures in multiple redundant systems. Coefficient values of failure rates for the Markov model are derived using the β factor model of the PDS (reliability of computer-based safety systems, Norwegian acronym) method. The blind shear ram preventer system of the subsea BOP components considers a demand rate to reflect reality more. Markov models considering the demand rate for one or two components are introduced. Two data sets are compared at the GoM OCS. The results show that three or four pipe ram preventers give similar availabilities, but redundant blind shear ram preventers or annular preventers enhance the availability of the subsea BOP. Also control systems (PODs) and connectors are contributable components to improve the availability of the subsea BOPs based on sensitivity analysis.

Static Soil Resistance to Pipe Ramming in Granular Soils

AbstractPipe ramming is a cost-effective trenchless pipe installation method in which percussive blows generated by a pneumatically or hydraulically powered encased piston rammer are used to advance a pipe or culvert through the ground. To evaluate the feasibility of a pipe ramming installation, engineers must be able to reliably predict the pipe drivability and installation stresses. Assessment of the drivability of the pipe and selection of the optimal hammer for pipe ramming installation requires that the static and dynamic soil resistance to ramming at the pipe face and along the casing be reliably estimated. However, pipe ramming-specific models are not currently available, and engineers often resort to the existing traditional pipe-jacking and microtunneling models for static soil resistance computations. This paper describes the results of four full-scale pipes rammed in the field and the corresponding static soil resistance to ramming in granular soils. A companion paper addresses dynamic soil res...

Analysis of a 610-mm-Diameter Pipe Installed Using Pipe Ramming

AbstractDepartments of transportation are increasingly embracing pipe ramming for culvert installation under roadways due to its cost effectiveness and ability to mitigate problems associated with open-cut trenching. Despite the increase in use, little technical guidance is available for the engineering of pipe-ramming installations. This study presents the analysis of the performance of an instrumented 610-mm-diameter steel pipe installed using pipe ramming. Measurements include ground surface movement and dynamic force and velocity waveforms to obtain driving stresses, hammer-pipe energy transfer, and static and dynamic soil resistance during the installation. Ground movements are compared to existing settlement prediction models. Inverted normal probability distribution models commonly used in tunnel engineering were evaluated and were observed to capture the observed settlement close to the center of the pipe but did not accurately predict the observed transverse settlement profiles. The transfer of e...

Preliminary Design and Engineering of Pipe Ramming Installations

AbstractInstallation of new buried pipes and culverts, and replacement of existing ones utilizing trenchless technologies, is increasing in popularity because these methods mitigate many of the surface disturbances associated with conventional open-cut placement. Pipe ramming is an efficient technique that allows installation of casings in soils that can present difficulties for other trenchless technologies. Despite increasing usage, little technical guidance is available to owners and engineers who plan installations with pipe ramming. This paper provides an overview of the pipe ramming technique, possible design procedures, and governing mechanics associated with pipe ramming, with the goal of providing a baseline for engineered installations and identifying areas for further research. Methods to estimate soil resistance to ramming, analysis of ground deformations, and ground vibrations are discussed and compared with measurements observed in field installations. Soil resistance predictions based on co...

An Innovative Ultradeepwater Subsea Blowout Preventer Control System Using Shape-Memory Alloy Actuators

This paper presents an innovative undersea blowout preventer (BOP) using shape-memory alloy (SMA). The new device using SMA actuators could easily be implemented into existing conventional subsea control system so that they can work solely or as a backup of other methods. Most important, the innovative all-electric BOP will provide much faster response than its hydraulic counterpart and will improve safety for subsea drilling. To demonstrate the feasibility of such a device, a proof-of-concept prototype of a pipe RAM type BOP with SMA actuation has been designed, fabricated, and tested at the University of Houston. The BOP actuator uses strands of SMA wires to achieve large force and large displacement in a remarkably small space. Experimental results demonstrate that the BOP can be activated and fully closed in less than 10s. The concept of this innovative device is illustrated, and detailed comparisons of the response time for hydraulic and nitinol SMA actuation mechanisms are included. This preliminary research reveals the potential of smart material technology in subsea drilling systems.

Utilization of Trenchless Construction Methods in Mainland China to Sustain Urban Infrastructure

Traditional methods of underground utility installation and replacement generally employ conventional open cut methods. These trenching methods in most urbanized settings typically create road closures, traffic delays, unnecessary detours, loss of access to homes and business, unsightliness, noise, and general disruption. Faced with population growth and an aging underground utility system, China has looked to emerging technologies to assist in providing sustainable solutions to addressing this situation. Three trenchless construction methods that have currently been adopted in China are horizontal directional drilling (HDD), pipe bursting, and pipe ramming. HDD is a technique that enables the installation of conduits and pipelines with minimum need for open-cut surface excavation. Pipe bursting is an accepted method for trenchless pipe replacement where an existing sewer or utility pipeline is replaced with a totally new structural pipe of equal or greater inside diameter. Pipe ramming is an established technology that provides a cost efficient alternative for placing steel casings under roads, railroads, finished landscapes, and structures. This paper describes each of the three trenchless construction methods and discusses several applications for sustaining underground utility networks through case histories of successful projects in China.

Instability of a cylindrical shell under three-point bending

The instability of a cylindrical shell under three point bending is considered. The problem has application to the industrial pipe ram bending process. The loading is idealized as a set of pads of uniform radial pressure in the regions of die-shell contact. A theoretical solution for the smallest buckling load is developed, using the Donnell and Sanders linearized stability equations. A finite element solution is also presented. The paper concludes with a discussion of results, from the two methods.

Comparison of elastic solutions for three-point bending of curved pipes

In this paper the linear elastic shell theory problem of the three-point bending of a curved pipe is considered. Such a loading arises in the industrial pipe ram bending process. Summaries are given for solutions to this problem based on the Mushtari-Vlasov-Donnel (MVD) and Sanders linear shell theories. Numerical results for displacements and stresses are obtained using the two shell theories, and these are compared with results from the finite element method (FEM). The present study gives practical information about the behavior of curved pipes subjected to ram bending. As well it provides information about the solution characteristics of thin-shell theories in toroidal coordinates.