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ASME Conference Presenter Attendance Policy and Archival Proceedings

2017;():V001T00A001. doi:10.1115/IPG2017-NS.
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This online compilation of papers from the ASME 2017 International Pipeline Geotechnical Conference (IPG2017) represents the archival version of the Conference Proceedings. According to ASME’s conference presenter attendance policy, if a paper is not presented at the Conference by an author of the paper, the paper will not be published in the official archival Proceedings, which are registered with the Library of Congress and are submitted for abstracting and indexing. The paper also will not be published in The ASME Digital Collection and may not be cited as a published paper.

Commentary by Dr. Valentin Fuster

Geohazard Considerations for Design and Construction

2017;():V001T01A001. doi:10.1115/IPG2017-2520.

The design and construction planning of pipelines is a multidisciplinary effort that requires support and input from geotechnical, geomatics and pipeline construction specialists. The cooperation between those disciplines is more pronounced and required when the pipeline traverses rugged mountainous areas with challenging settings. This paper begins by considering the range of topographic, geological, construction and other route datasets and how they are generated. A presentation of an application that has been developed and utilizes progressively improving route datasets as projects advance to generate Right-of-Way (ROW) footprint and detailed construction quantities such as granular excavation volumes, supply and demand quantities and cross-section details is introduced. An overview of construction details including construction direction, seasonality, and ROW profile is then offered. In addition, several analytical methods are available for deployment, each being suited for various stages of a project’s development. These analytical methods include advanced workbooks and GIS Enabled Applications that leverages DTM information as well as commercially available packages. A discussion of these methods is presented together with suggested guidelines as to when to apply them in a proposed project’s phase. Finally, lessons learnt from the experiences gained in several major projects are summarized.

Topics: Pipelines
Commentary by Dr. Valentin Fuster
2017;():V001T01A002. doi:10.1115/IPG2017-2527.

This article aims to describe the best industry practices followed by the line maintenance area of the Ocensa pipeline, which can be divided into 4 large steps that follow a PHVA cycle of the activity, which includes relief planning, the execution of the same, the verification and geotechnical monitoring, closure and feedback.

Commentary by Dr. Valentin Fuster
2017;():V001T01A003. doi:10.1115/IPG2017-2546.

TGN operates a system of 9,000 kilometers, with a long stretch traveling next to the foothills. Although it is clear now that this path may not be the best choice, it was defined for access convenience parallel to a national highway back in 1960, when erosion was not an important issue. Whenever a pipeline crossing is located at a place where a river experiences a break in its slope, development of meanders poses a significant threat to its integrity. The interaction between a rigid structure and a changing environment sets the scenario of a problem that needs constant attention. Thus, meanders become the main cause that leads to the implementation of expensive remediation works. In the following paragraphs, a method of evaluating meanders is presented based on concepts of channel stability regarding river curvature, width, slope and flows. This is complemented with real cases in which theoretical aspects are matched with actual crossings, its construction characteristics and the evolution of meanders with time. Long term performance of typical solutions such as soil movement channeling, bank protections, jetties and pipeline lowering are compared. Finally the inverse problem is addressed in which guidelines for the design of a new crossing are listed.

Topics: Rivers , Hazards
Commentary by Dr. Valentin Fuster

Geohazard Risk Assessment and Pipeline Integrity Management Planning

2017;():V001T02A001. doi:10.1115/IPG2017-2505.

Pipeline geohazard assessment is becoming recognized by operators and regulators as an increasingly important constituent of overall integrity management and iterative risk assessment of pipelines. An ongoing challenge in assessing the threat posed to a pipeline by various geohazard mechanisms within the B31.8S category of Weather-related and Outside Force is the degree of uncertainty associated with estimates of frequency of occurrence, vulnerability, and loss of containment for individual and cospatial geohazard mechanisms. When combined with threats of other types, such as corrosion and third party damage, estimates of geohazard occurrence frequency and their associated frequency (or probability) of loss of containment may seem imprecise and uncertain. This paper discusses a framework for assessing geohazard susceptibility and the associated uncertainty, and means of incorporating and communicating uncertainty in hazard and risk assessments. Examples are provided from a case study in Perú.

Commentary by Dr. Valentin Fuster
2017;():V001T02A002. doi:10.1115/IPG2017-2508.

The Weather and External Forces hazard (WEF) is considered in ASME B31.8 as a non-time-dependent hazard due to its random nature and the high uncertainty of the effects on pipelines given the occurrence of natural events, especially associated with hydro and geotechnical processes. Although there is a wide range of events associated with geological, hydrological and hydraulic conditions (among other things) that can affect a certain infrastructure, only a limited number of these geohazards can cause direct damage to hydrocarbon transportation infrastructure.

The identification and understanding of a ground failure process and its association with the susceptibility or physical fragility of the pipeline facing the potential adverse effects of a hazard event, allow to estimate the conditional probability of pipeline failure under loading stresses induced by the event and to estimate the actions needed to mitigate this hazard with methodologies ranging from approaches of structured expert knowledge to methods of structured analysis that incorporate incorporating subsurface investigation, detailed study of the results from terrain monitoring, pipeline and triggering agents through mechanical modeling.

This document presents a technical proposal for the management of geohazards which, due to the nature and characteristics of the instability processes and its relation with the activity of triggering agents, and the vulnerability of the pipeline, allow them to be analyzed as time dependent.

Topics: Hazards
Commentary by Dr. Valentin Fuster
2017;():V001T02A003. doi:10.1115/IPG2017-2512.

Pipelines crossing mountainous areas are susceptible to ground movement loading from landslides. Structural analysis of pipeline performance from landslide loads is critical for making decisions on the requirement and timing of intervention activities. Current analytical assessment methodologies for pipelines affected by ground movement tend to assume the landslide as an abrupt boundary from the stable region to moving ground, causing an over conservative estimation of the condition of the pipeline. In-line inspection using inertial mapping tools provides invaluable information to assist in the determination of the current pipeline integrity but does not provide a complete picture because axial loads are not defined. Interpretation of in-line inspection data allows the estimation of a transition zone width between stable and unstable ground, where there is a progressive increase in ground movement. Due allowance for the transition zone can remove conservatisms in the assessment methodology and allow a pipeline integrity plan to be created.

This paper investigates the influence of landslide transition zone dimensions on the pipeline response and a methodology is developed for the prediction of the transition zone width. The interaction between the ground and the pipe movement is modelled using finite element analysis techniques.

The definition of the transition zone properties provides a more reliable prediction of the pipeline performance and enables the current and future pipe integrity to be established with greater confidence.

Commentary by Dr. Valentin Fuster
2017;():V001T02A004. doi:10.1115/IPG2017-2513.

Hydrocarbon pipelines are exposed to hazards from natural processes, which may affect their integrity and trigger processes that have consequences on the environment.

Among the natural hazards are the effects of the earthquakes, the neotectonic activity, the volcanism, the weathering of soils and rocks, the landslides, the flows or avalanches of mud or debris, the processes related to sediment transport such as the erosion, the scour by streams, the floods and the sloughing due to rains. Those processes are sometimes related to each other, e.g. the earthquakes can produce slides, or movement of geological faults, or soil liquefaction; the rain can trigger landslides and can cause avalanches and mudslides or debris flow; the volcanic eruptions can originate landslides and avalanches, or pyroclastic flows. Human activities can also induce or accelerate “natural” processes that affect the integrity of the pipelines.

The strength and stiffness of the pipelines allow them to tolerate the effects of natural hazards for some period of time. The amount of time depends on the strength and deformability, the stress state, the age, the conditions of installation and operation of the pipelines and their geometric arrangement with regard to the hazardous processes.

In the programs for pipeline integrity management, the risk is defined as a function that relates the probability of the pipeline rupture and the consequences of the failure. However, some people define risk as the summation of the indicators of probability and consequences, such as a RAM matrix. Others define the risk as the product of the probability of failure times the cost of the consequences, while the overall function used to evaluate the rupture probability of a pipeline facing hazards considered in the ASME b31.8 S standard includes all the elements involved in the failure process. In that standard, for the specific analysis of natural hazards, it is proposed that the function is separated in the two following principal elements: the probability of occurrence of the threatening process (hazard) and the pipeline’s capacity to tolerate it. In this paper a general function is proposed, which is the product of the probability of occurrence of the threatening process, the vulnerability of the pipeline (expressed as the fraction of the potential damage the pipe can undergo), and the consequences of the pipeline failure (represented in the summation of the costs of the spilled product, its collection, the pipeline repair and the damages made by the rupture).

Commentary by Dr. Valentin Fuster
2017;():V001T02A005. doi:10.1115/IPG2017-2517.

Integrity Management on Cenit common Right-of-Way (ROW), contemplate a preventive vision respect the impact that new infrastructure projects can cause in hydrocarbon transportation systems directly and indirectly. By including the management of Climate and External Forces Threat from this preventive approach have been identified mitigation and/or maintenance actions of which must be considered in the arrangements of common right-of-way with external entities responsible for the planning, construction and operation of these projects. This document presents the management strategy that was built an implemented largely, and the exposed examples are intended to show the importance of incorporates these learned lessons in the management of geotechnical assurance of the ROW.

Commentary by Dr. Valentin Fuster
2017;():V001T02A006. doi:10.1115/IPG2017-2528.

This paper presents a probabilistic approach for the assessment of the Weather and External Forces hazard in pipelines using a Bayesian Belief Network. Such model was constructed through structured expert judgment methods for those factors whose deterministic modelling is complex or unknown and existent models for those known factors or previously studied phenomena. For the hazard modelling, three fundamental groups of variables were considered: susceptibility, triggering events and vulnerability. Through this proposal, the hazard is described from a probabilistic perspective, including the uncertainty associated with instability processes, information gathering and analysis and risk perception, among others. A transportation system characterized by its high geotechnical complexity is used as a case study, and results were compared with the current assessment model. The results show that the new model has greater sensitivity to the hazard level while being consistent with both the condition of the Right of Way (ROW) and the hydrocarbon transportation infrastructure.

Topics: Hazards
Commentary by Dr. Valentin Fuster
2017;():V001T02A007. doi:10.1115/IPG2017-2529.

This paper presents the climatic zoning in the Rights-Of-Way (ROW) of Cenit’s infrastructure, in which the spatial and temporal distribution of rainfall was determined by analyzing precipitation information in a time window of 30 years. Rains influence on the ROW stability are exposed in two cases of study, using climatic zoning as a fundamental basis for understanding its effects. The analysis of these case studies allows establishing guidelines for the geohazard management during rainy seasons.

Topics: Stability , Climate
Commentary by Dr. Valentin Fuster
2017;():V001T02A008. doi:10.1115/IPG2017-2531.

Establishing pipeline failure frequencies enables designers and operators to make informed decisions on the allocation of resources to address different threats. Normally, this would involve the selection and timing of inspection, monitoring and protection activities. Typically, failure frequencies are defined based on the collection of historical statistics. This is difficult for geohazards due to the comparatively low incident rate compared to other hazards, however the consequences tend to be catastrophic. As a result, significant uncertainties are attached to predicted failure frequencies for geohazards.

Two principal areas of uncertainty cover the occurrence and nature of loading events and whether the pipeline will survive the loading. This paper addresses both of these key aspects. The occurrence and nature of loading can be determined from the examination of in-line inspection records through different terrains. The pipeline survival rate is based on the efficient execution of multiple analysis runs within a finite element code where the distributions of the key input variables are defined to cover either observed or potential variation in the field. These include landslide size, orientation, movement and soil stiffness values as well as considerations of tensile fracture limits. The calculation of the probability of pipeline failure due to landslide loading is illustrated using a case study.

Commentary by Dr. Valentin Fuster
2017;():V001T02A009. doi:10.1115/IPG2017-2537.

To control the threats from external forces, pipeline owners and operators require detailed information about their pipeline infrastructure and the environment surrounding that infrastructure. The contribution from geographic data is recognized as an increasingly important part of a complete integrity management program, particularly for the identification of geohazards. This is because geohazards are generally characterized by high spatial variability, are complex and difficult to quantify but may result in catastrophic failure of pipelines.

In recent years we have seen widespread technological development surrounding the processes to capture information in order to deliver quantitative inputs for pipeline engineers, risk & geotechnical experts. International codes & best practices (e.g. AS 2885.1-2012) state that “Environmental impact assessment is not simply a vehicle to obtain regulatory approval, it is a critical element of the planning for design, construction and operation of the pipeline.” Furthermore, geohazards frequently develop during the service life of pipelines. Consequently, regulators recommend that assessments are conducted on an ongoing basis to identify all potential threats and implement mitigation measures.

A process has been developed to create efficient and economical solutions for monitoring and assessing the significance of pipeline bending strain and whether actual movement has taken place. This process can make use of a variety of inputs including slope gradient, climate, groundwater conditions, slope instability, seismic intensity, and environmental impacts, and can provide important information in the determination of potential mitigations. This paper will review the benefits which can be gained from the implementation of integrated approaches to inform geohazard management.

Commentary by Dr. Valentin Fuster
2017;():V001T02A010. doi:10.1115/IPG2017-2538.

Due to the importance for the Oil and Gas Industry to have a technical document that consolidates the knowledge on management of geohazards for Latin America, the Geotechnics Project Team (EPGEO under its acronym in Spanish) of the Regional Association of Oil, Gas and Biofuels Sector Companies in Latin America and the Caribbean (ARPEL) developed the “Guidelines for Monitoring and Inspection of Pipeline Integrity Management to Face Geohazards” between 2014 and 2016. These guidelines contain the experience of the different operators in the region, given the highly-complex geological-geotechnical pipeline routes (due to the mountain range of the Andes in South America or the Central System in Central America), as well as the high technical requirement derived from the dynamics of the triggering agents in equatorial and tropical areas. In this respect, this document presents the main results of such consolidation and its dissemination, some relevant aspects to be taken into account in interdisciplinary works with reference to third parties, as well as the new guidelines that the EPGEO has proposed to develop that complement the management of geohazards in a Pipeline Transportation System (PTS).

Commentary by Dr. Valentin Fuster
2017;():V001T02A011. doi:10.1115/IPG2017-2545.

The transportation system for hydrocarbons consists of an important and complex network of pipelines used by oil and gas logistics companies, designed to quickly and efficiently transport oil and gas from its origin, to areas of some demand along territory where operates. Currently Brazil has 15,000 km of transportation pipelines within about 7,500 km of right-of-way pipelines. Along its territorial extension it faces several influences along its route, being the main ones influenced by the external hazards from nature and by third party actions. TRANSPETRO has about 450 water crossings in cataloged water bodies currently. These crossings are currently characterized only according to their geometric characteristics, not considering several aspects inherent to them. The inspections at these crossings are laborious and have a high cost due to necessity of divers and bathymetry in some cases.

To monitor the condition of all pipeline water crossings it is important to ensure the pipeline integrity. Depending on hydraulic phenomena, it is possible result in an exposure of the pipelines, free spans, changes in the original pipeline or excessive vibration. These changes can generate high mechanical stresses with both static and dynamic loads. The present study was characterized by the development of a methodology for assessing the susceptibility to the exposure of pipelines as a result of the hydrological hazards present at the crossings in which they are found. Moreover, this evaluation methodology offers a tool to define inspection extent and frequency, as well as the corresponding risk control actions. For this purpose, a pipeline management program has been set up, which consists in the definition of water crossings that constitute a potential hydrological hazard and where they can interact with the pipeline considering the probability of a specific hydrotechnical hazard leading the pipeline the exposure.

As a result of this research it was defined a methodology to characterize pipeline crossing areas as well as field survey, evaluation of the susceptibility of pipeline exposure at crossings and the programming of control actions were defined according to the susceptibility found. Finally, the study has also presented a cost analysis of crossings inspections comparing the traditional method to the new premises adopted in this project.

Commentary by Dr. Valentin Fuster

Monitoring, Mitigation and Emergency Repairs

2017;():V001T03A001. doi:10.1115/IPG2017-2503.

Many pipelines are built in regions affected by harsh environmental conditions where changes in soil texture between winter and summer increase the likelihood of risks. Pipeline routes also cross the mountains that are characterized by steep slopes and unstable soils as in the Andes and along the coastal range of Brazil. In other cases, these pipelines are laid in remote areas with significant seismic activity or exposure to permafrost. Depending on weather conditions and location, visual inspection is difficult or even impossible and therefore remote sensing solutions for pipes offer significant advantages over conventional inspection techniques. Optical fibers can help solve these challenges. Optical fiber based geotechnical and structural monitoring use distributed measurement of strain and temperature thanks to the sensitivity of Brillouin scattering to mechanical and thermal stresses. The analysis of scattering combined with a time domain technique allows the measurement of strain and temperature profiles. Temperature measurement is carried out to control soil erosion or dune migration through event quantification and spatial location. Direct measurement of strain in the soil also improves the detection of environmental hazards. As an example the technology can pinpoint the early signs of landslide. In some cases, pipe actual deformation must be monitored such as in case of active tectonic fault crossing. Pipe deformation monitoring operation is achieved by the measurement of distributed strain along fiber sensors attached to the structure. This paper comprehensively reviews over 10 years of continuous development from technology qualification and validation to its implementation in real cases as well as its successful continuous operation. Case studies present pipeline monitoring in Arctic and Siberian environment as well as in the Andes. They illustrate how the technology is used and demonstrate proof of early detection and location of events such as erosion, landslide, subsidence and pipe deformation.

Topics: Fibers , Pipelines
Commentary by Dr. Valentin Fuster
2017;():V001T03A002. doi:10.1115/IPG2017-2509.

Unmanned aerial vehicles (UAV), also known as drones, have become a very reliable and convenient tool to many engineering applications. Pipeline corridors are often exposed to geotechnical risk that may interrupt proper service. The risk sources vary, and range from steep hills to many site conditions such as ancient landslides, changes on phreatic water level, creeping soils, or geomorphological changes on the environment. Knowing and understanding the level of risk is highly dependent on identifying any geotechnical hazard in due time, before it materializes. Pipeline corridors are measured in kilometers, and the area that may adversely affect the corridor can vary from a few meters to several hundred on each side of the corridor. This paper presents an application of UAV based digital photogrammetry to evaluate and monitor the hazard and evolution of the site PK 469 OCENSA km 149 ODC. The site is maintained by Oleoducto Central S.A. (OCENSA), and the paper describes the different geotechnical studies and works carried out to maintain uninterrupted service of the pipeline. The paper includes technical information supporting the processing and characteristics of the photogrammetry based evaluation and monitoring method, to highlight the efficiency and accuracy of the proposed method.

Commentary by Dr. Valentin Fuster
2017;():V001T03A003. doi:10.1115/IPG2017-2510.

The 408 km × 34" PERULNG pipeline (operated by Hunt LNG Operating Company) is monitored in its first 62 km by a geotechnical fiber optic cable, since these first 62 km are exposed to major geohazard threats such as landslides, large river crossings, high slopes, bofedales, etc.

The fiber optic cable geotechnical monitoring relies on the measurement of strain and temperature in the pipeline right-of-way.

Due to the continuous and real-time monitoring of the duct, it was possible to detect a tension cracking near KP 25 + 600 as an abnormal temperature change was captured by the temperature sensing cable; also near KP 27 + 900 and KP 34 + 750 unusual cable stresses were detected which announced landslides of the rotational type in both locations.

In these three cases, protection decisions could be taken to secure pipeline’s integrity.

Commentary by Dr. Valentin Fuster
2017;():V001T03A004. doi:10.1115/IPG2017-2511.

The OCENSA pipeline crosses the Valley of the Magdalena river flood on its way to the Caribbean Sea, the area of the valley is commonly inundated during the rainy season on shallow waters that remain flooded swamps. These swamps soils are composed by extremely soft peat with thicknesses greater than 15 meters. In June 2016 started the construction of a highway with an embankment of 6 meters in height which was more than 30 meters away from the OCENSA 30” pipeline, Due to the high compressibility of peat, to construct the road the soil is subjected to a process of consolidation and the height of the embankment was corrected adding more material. In July 29 2016 occurs a failure by load capacity on the ground under the embankment and as a result of this fault a lateral displacement of the adjacent soil producing a horizontal displacement in the pipeline of more than 50 cm. This document shows results from the affectation to the pipe and the measures taken to correct the situation.

Commentary by Dr. Valentin Fuster
2017;():V001T03A005. doi:10.1115/IPG2017-2518.

In slope movements with slow strain rates that affect rights of way (ROW) or its surrounding areas, an appropriate Inline Inspection (ILI) program with inertial modules may provide timely and quality information, with ease of matching with geotechnical events and lower costs than conventional monitoring methods. In virtue of above, for structural integrity management of pipeline, this information is necessary and its integration with the information obtained from other sources such as ROW patrol, terrain monitoring and pipeline monitoring. This document contains information related to the tracing, analysis and executed activities in the study case located in Colombian center-west, where neotectonic effects and a common ROW with a main highway converged.

Topics: Pipelines
Commentary by Dr. Valentin Fuster
2017;():V001T03A006. doi:10.1115/IPG2017-2524.

The present paper presents the analysis, carried out by the Ocensa pipeline, against a case of longitudinal or axial landslide to the pipeline in the KM 35 + 690, starting from the identification by inertial tool, the geotechnical characterization and the analysis of Soil-pipe interaction, excavation and stress relief and the techniques used to mitigate the effects of sliding on the pipe.

Topics: Pipelines , Landslides
Commentary by Dr. Valentin Fuster
2017;():V001T03A007. doi:10.1115/IPG2017-2526.

Oil pipelines and gas pipelines usually go through geotechnically unstable areas for different reasons. These can go from situations related to the engineering stage (trace), to environmental and social aspects during the construction process. Due to these aspects, the ducts go through geotechnically undesirable areas. Usually, the geotechnical instabilities, according to the kind of movement, are low speed (cm/year), medium (m/year) and very quick processes that generate movements of tens to hundreds of meters per day. Most of Mass Removal Phenomenon (MRF) are triggered by rain and/or earthquakes and are translated into land movements which at the same time involve, occasionally, important deformations in pipelines or its breaking, depending on the movement speed and the possibility of making works before the pipeline breaking. To get to know the pipeline tensional state from the beginning of the pipeline operation, in this unstable zones, is an essential task, which depends on the early identification of the said land movements and the possibility to do measurements on the pipelines using tools such as In-line inspection running (ILI) or the installation of strain gauges. This situation makes the task of monitoring in unstable zones a vital one. The current paper is based on a breaking pipeline case due to soil movement, “monitored by inclinometers”, with the purpose to show the importance of a geotechnical and mechanical instrumentation that offers useful results. The instrumentation allows to model the interaction soil-pipeline to accomplish relevant tasks, that avoid the pipeline breaking and at the same time allow to stablish deformation thresholds of soil or pipeline, which will become early warnings to avoid breakings. Furthermore, the soil and pipeline’s deformation thresholds are documented, based on a system transport by pipelines (STP) breaking cases, to stablish threat classifications to a specific pipeline.

The called instrument reading in real time implies: detection, measurement and data broadcasting that allows the user to have daily records of the movements or required associated variables, with no need to depend on other communication systems that might be inexistent in some areas. This paper also shows the development and operation of a monitoring station that includes: inclinometers, piezometers, strain gauges and rain gauges, among others. These broadcast their data to a server that the user has access to, from any place with a Wi-Fi network, here the user will be able to display information from each one of the instruments, emphasizing the measured variables or magnitudes (displacement, water level, micro strain mm/day) into graphics. The station has a limitation over battery length of 6 months, when it’s problematic to install a recharge solar cell system.

Commentary by Dr. Valentin Fuster
2017;():V001T03A008. doi:10.1115/IPG2017-2541.

The Camisea’s Pipeline Transportation System (PTS) in Peru, owned by Transportadora de Gas del Perú (TgP) and operated by Compañía Operadora de Gas del Amazonas (COGA), stars in the Amazon rainforest, crosses the Andes Mountain (4850masl) and descends finally towards the coast of the Pacific. The PTS has more than 10 years of operation and it has two pipelines: one transports Natural Gas (NG) and the other Natural Gas Liquids (NGL) pipelines. The NG pipeline has a length of 864km including a Loop pipeline of 135km. The NGL pipeline has a length of 557km.

Because of particular physiographic conditions of each geographic sector that cross the right-of-way (ROW), the integrity of the PTS acquires a level of significant susceptibility to the occurrence of geohazard, which are the product of natural erosive processes and mass movements.

In the coast sector, one of the most representative processes of geotechnical instability is the soil or debris flow (mass movements of soils). The occurrence of this type of flow has a greater incidence in the torrential creek, which generate transport of large volumes of sediments during rainy seasons. The flow has destructive effects and therefore, it is necessary to analyze the geomorphological, geological and hydrological aspects of the main creek and rivers that crosses the ROW with the objective of maintaining the integrity of the pipelines. In Peru, the flows are associated and known as Huayco or Huaico.

As an additional component, it is highlight that the Peruvian coast is located within the area of interaction between the South American Continental Plate and the Nazca Plate, where there is evidence of seismic activity with different magnitude that influence on the occurrence of geo-dynamic processes with certain periods of frequency that could change the terrane’s morphology.

The current article describes technical aspects of identification, intervention, monitoring, and geotechnical control in sub-fluvial crossings with levels of potential damage to the geohazard defined as huayco in the integrity management program of PTS. This activity include 63 main sub-fluvial crosses, approximately 30% are of the seasonal flow regime, located in the coast zone; at the same time, these are tributary to main rivers of constant flow as is the case of the Pisco, Cañete and Mala rivers. In this paper, it is place a special emphasis on the fourth crossing of the Huáncano creek, because it is a place of potential impact in the occurrence of soil flows.

Within the annual geotechnical maintenance of the sub-fluvial crosses, in the part of the Peruvian coast, for the operation of the PTS of TgP, bed and banks protection some works are implemented, such as: Check dams, re-channeling, levees and stone riprap (Stone armour). Likewise, a program of evaluation and technical inspection is develop: it includes the analysis of the expected levels of undermining and performance condition of the existing works, which allow defining the geotechnical intervention in a term according to the identified risk level. All in all framed within a process of permanent geotechnical monitoring of the right of way.

Finally, it is highlighted that to date the application of the process described above has been continued, which has facilitated the development and continuous assessment of the risk condition by huaycos in the PTS of TgP. This program has maintained an operation with an acceptable level of risk in the areas of interest and avoiding problems and consequences of great impact to communities, the environment and the operation of the system.

Commentary by Dr. Valentin Fuster
2017;():V001T03A009. doi:10.1115/IPG2017-2547.

Employing published information and sharing monitoring apparatus and studies, were the initial solution adopted to reach a rain monitoring process in Transpetro (Petrobras Transporte S.A.) southern ROWs. This type of approach can be easily establish and allows the operator to reach satisfactory results, especially for those that has no controlled process at all, where a small amount of information leads for some result even if it is to clarify the need and the resources for such kind of approach.

Even being quite conservative and bit superficially, the process recently established in Transpetro, has already brought a slight economy and safety. Aiming to show the process flow, this paper does not concentrates in reflecting the trigger point, instead it reflects the experience and general methods applied for checking forecasts and rainfall index.

Commentary by Dr. Valentin Fuster

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