Pipeline Installation Research Articles

Short-Term Response of Deep-Water Benthic Megafauna to Installation of a Pipeline Over a Depth Gradient on the Angolan Slope

Large structures are introduced into deep-water marine environments by several industrial activities, including hydrocarbon exploitation. Anthropogenic structures can alter ecosystem structure and functioning in many marine ecosystems but the responses on continental margins are poorly known. Here, we investigate the short-term response of benthic megafauna to the installation of a 56 km-long 30 cm diameter pipeline on the Angolan Margin (Block 31) from 700 to 1800 m water depth using remotely operated vehicle imagery. Clear depth-related patterns exist in the density, diversity and community structure of megafauna observed in 2013 prior to pipeline installation. These patterns are altered in a subsequent survey in 2014, three-months after pipeline installation. Significant increases in density, particularly in mid-slope regions are observed. Diversity is generally, but not consistently, enhanced, particularly in the shallower areas in 2014. Clear changes are noted in community structure between years. These changes are primarily caused by increases in the abundance of echinoderms, particularly the echinoid Phormosoma sp. indet. There was no evidence of colonisation of the pipeline in three months by visible fauna. The few large anemones observed attached to the pipe may be able to move as adults. The pipeline appeared to trap organic material and anthropogenic litter, and may enhance available food resources locally as well as providing hard substratum. These results indicate complex and ecosystem-dependent responses to structure installation and caution against simplistic approaches to environmental management.

Experimental investigation on a floating multi-effect solar still with rising seawater film

In this paper, a floating multi-effect solar still using parabolic concentrators to directly heat rising seawater film is investigated. The novel desalination device integrates solar still and two concentrators as a whole, which avoids the installation of a heat exchange pipeline and can float on the ocean to produce freshwater. The floating still consists of a front parabolic concentrator, a rear parabolic concentrator, and several embedded distillation cells. The distillation cell is composed of a hydrophilic wick, a condensing plate, and a narrow space in between. The parabolic concentrator greatly increases the solar heat to improve the temperature gradient and enhance the phase transition and diffusion process of water vapor. During desalination, the rising seawater film for evaporation is formed in the hydrophilic wick by capillary force. Through indoor steady-state experiments, some key parameters such as solar irradiance and incident angle on the temperature, water yield and gain output ratio (GOR) of the still were studied. Results indicate that the maximum temperature gradient in the 5-effect still can reach 48.5 °C. Under a 900 W/m2 irradiation, the water productivity and GOR are 2.7 kg/m2/h and 2.2, respectively. Additionally, outdoor experiments show that the daily freshwater reaches 4.7 kg/m2 with an average irradiation of 543 W/m2.

Redesign Model Instalasi Pipa Saluran Air Bersih Di Desa Toniku Jailolo Selatan

The purpose of the service program to redesign the installation of clean water pipelines is to provide new installations and repair clean water distribution pumps that are able to distribute clean water originating from river water in the Toniku Village area so that the water distribution system runs more evenly, both to the reservoir and to the reservoir. the community directly. The implementation of the activity begins with an initial survey to see the condition of the artificial wells and water reservoirs that will be repaired where there are artificial wells installed on the banks of the river. Repairs to the pipe installation are carried out by replacing 2 4-inch pipes so that the flow of water that will enter the reservoir does not suffer losses or is wasted. The initial design before the change was that there were many pipe connections that were installed from the pump to the reservoir so that the water flowing into the reservoir experienced a lot of loss or wasted a lot. From the results of the field review, the electrical capacity to drive the pump is not sufficient because the type of electrical cable connected is not suitable or unable to drive the two pumps. Errors also occur in the installation of capacitors where the pump has a 40 F capacitor type but the one installed is 50 F. For the problem of electricity capacity, the village government has tried to coordinate with PLN to replace the power cable. As for the capacitor problem, in this program we bought 2 capacitors to be replaced and installed. Keywords: Redesign, Water Pump, Reservoir, Drain Installation

When Scientists and Industry Technologies Mitigate Habitat Loss: The First Bioconstruction Relocation in the Mediterranean Sea

The need for habitat recovery in coastal areas, especially those subjected to intensive exploitation, has increased because of significant historical loss and alteration of habitats and, therefore, adverse ecological impacts. The present study defines a stepwise approach to mitigate habitat loss in deep coastal environments, describing the planning, intervention, and monitoring phases following the Trans Adriatic Pipeline (TAP) laying along the Apulian coast (Adriatic Sea, Italy). Preliminary field activities encompassed morpho-bathymetric data (MBES and SSS), SCUBA and ROV observations to accurately map and characterize the mesophotic reefs built by invertebrates found in the area. The pipeline route interfered with 30 outcrops between 50 and 80 m depth, mostly colonized by 15 taxa/morphological groups. A functional/conservative approach was adopted to recognize the taxa/morphological groups on which to focus the removal and following relocation activities based on their abundance, conservation status, and functional traits. Saturation divers teams, ROV pilot technicians, and researchers collaborated to minimize the physical impact and the loss of organisms due to the pipeline installation. They relocated a total of 899 living portions (nuclei) from the 30 interfered reefs on the top of the pipeline. The following monitoring activities, carried out after fourteen months since the intervention, revealed a high mean survival rate (88.1%) and slight variations in the structure of the nuclei assemblages. This study represents a paradigmatic case of involvement and support of the private oil and gas sector to mitigate habitat loss in the Mediterranean Sea, and stresses the need for integrated management involving different stakeholders to mitigate the effects of the exploitation of marine resources through ante operam assessment and active restoration actions.

Vegetation Change in a Sand Prairie over Ten Years Following a Gas Pipeline Installation

Sand prairies experience relatively high rates of small-scale disturbance, feature a high complement of annual plant species, and are fairly dynamic in terms of year-to-year micro-scale species composition. In summer 2011, an underground natural gas pipeline was installed across Sand Prairie Natural History Reservation 19 km west of North Newton, KS. The resulting excavation left a strip 560 m long and 24 m wide devoid of aboveground vegetation. From August 2012 to 2021, I monitored vegetation composition in 60 0.75 × 0.75 m2 quadrats along six parallel transect lines: three lines along the center of the excavated area and three placed 20 m away in prairie unaffected by earth-moving vehicles. Quadrat species richness was higher in the undisturbed reference area in the first year, but higher in the pipeline area in four later years. There were no consistent area differences in species evenness. Annual species richness was higher within the pipeline area every year. In contrast, perennial species richness was higher in the reference area during the first seven years. Coverage by annuals was higher every year within the pipeline area, whereas coverage by perennials was consistently higher in the reference area. Bray-Curtis Similarity for the two areas ranged from 29.2 to 55.8% across years, but was not trending upward with time. Twenty-one species were restricted to the pipeline area; several other species were beginning to move from the reference area to the pipeline area. Both Floristic Quality Index and modified FQI were consistently higher for the reference area than for the pipeline area. It is too early to project the time frame for the pipeline area to recover a species composition indistinguishable from the undisturbed reference site, but clearly a period longer than ten years will be required.

LAYING OF PIPELINES IN SUBSEA TAKING INTO ACCOUNT THE PROTECTION OF THE ENVIRONMENT

This article is devoted to the construction of offshore pipelines, taking into account the protection of the environment. Initially, information was provided on the conditions of the pipelines. Then there was a discussion about the methods of laying pipelines, their pros and cons, and therefore the choice of method, which is economically viable and takes into account the environment. We know that the main factor in choosing any method of laying a submarine pipeline is economic and environmental factors. Underwater pipelines are invaluable for offshore oil and gas transportation and water supply to the islands. The construction method is very important for the installation of an expensive and time-consuming offshore pipeline and should be selected after a general consideration of equipment, capital and time. In addition, the environmental impact and safety of construction and its impact on surrounding marine operations are also determining factors. Decks, pipelines and cables, valves and switches, pumps, cleaning and all equipment must work without hindrance and must be tested repeatedly to avoid endangering people and the environment. At present, submarine gas pipelines continue to develop, accounting for 45% of natural gas exports to the west. Therefore, before the submarine is laid, the entire route along the seabed must be carefully studied, and all potential obstacles, including the sunken ship, large rocks must be identified, eliminated or bypassed. Subsea pipelines are the safest, most cost-effective, and most environmentally friendly route. Keywords: subsea pipelines, construction technologies, submarine pipeline installation, environment supervision, management and control of industrial waste, prevention of pollution, pipeline laying.

Discussion on Quality Control of Mechanical and Electrical Equipment and Pipeline Installation

Discussion on Quality Control of Mechanical and Electrical Equipment and Pipeline Installation

Multivariate tools to investigate the spatial contaminant distribution in a highly anthropized area (Gulf of Naples, Italy)

The Gulf of Naples located in a high anthropized coastal area is subjected to an infrastructural intervention for the installation of a submarine power pipeline. In order to evaluate the distribution of contaminants in the seafloor sediments, a preliminary study has been conducted in the area using multivariate techniques. The statistic approach was performed to gain insights on the occurrence of organic and inorganic contaminants within the area, aiming to identify the relevant hot spots. Three geographical sub-areas influenced by different contaminant association were recognized: Torre Annunziata (TA), Capri (CA), and middle offshore (MO). TA and CA resulted marked by a severe contamination pattern due to anthropogenic pressures. In addition, the influence of the depositional basin in governing the contamination trend has been pointed out. The supervised technique PLS_DA resulted to be a powerful tool in addressing the complexity of the huge dataset acquired during the marine survey, highlighting the main trends in the variability of quality indicators, orienting thus the deeper investigations during follow-up monitoring activities.

Mechanical properties of glass fibre reinforced pipeline during the laying process

ABSTRACT Based on the catenary equation, the total suspended length of the pipe, the location of the touch down point (TDP), and the tension at the top were determined. A lumped-mass model was used to discretise the cable dynamics over the length of the GFRP pipeline. The Morison equation is widely used in the engineering field. As the top boundary condition of pipeline laying in the overall analysis, the motion response of the vessel is a crucial external load in the design of submarine pipelines. Based on the finite element numerical simulation, the dynamic response characteristics of GFRP pipeline laying under different wave conditions were systematically studied. The influences of the laying angle and submerged weights on the dynamic response of pipeline laying were discussed. Finally, factors affecting pipeline installation stability were summarised and suggestions for practical engineering were proposed.

The Correlation of Working Posture toward Complaints of Musculoskeletal Disorders on Pipeline Installation Workers

Introduction: Unergonomic working posture is one of the causes of musculoskeletal disorders. Musculoskeletal disorders (MSDs) can be affected by factors such as working hours, age, and posture. If the working posture is not done correctly, it may cause disorders of the muscles, bones, tendons, and nervous system. This study aims to analyze the correlation of working posture toward complaints of musculoskeletal disorders (MSDs) on pipeline installation workers of a state-owned water utility company (PDAM). Methods: The design of this study was a descriptive qualitative with a cross-sectional design. The sample in the study consisted of 30 workers selected by a total sampling method. The variables in this study were working postures whose data were obtained using the Quick Exposure Checklist (QEC) instrument and musculoskeletal disorders (MSDs) whose data were obtained using the Nordic Body Map (NBM) instrument. The data analysis used in this study was a gamma correlation test. Results: According to the results obtained, for actions that need to be investigated further and changed soon, 55.6% had a high category, and 44.4% had a very high category of musculoskeletal complaints. Meanwhile, in the category of acts that need to be investigated and changed immediately, 15.4% had moderate musculoskeletal complaints, 15.4% had high musculoskeletal complaints, and 69.2% had very high musculoskeletal complaints. According to the results of the correlation test between the working posture variable and the symptoms of musculoskeletal disorders (MSDs), the significance value obtained was 0.000 and the coefficient value obtained was 0.752. Conclusion: There was a significant and strong positive relationship between the two variables, that is, the higher the working posture value, the higher the main complaints of musculoskeletal disorders (MSDs).Keywords: work posture, musculoskeletal disorders (MSDs), pipeline installation workers

Recycling of Excavated Soils from Mini-Trenches Made on Road or Sidewalks to Install Public Utilities

Digging trenches on roads, sidewalks, or banks to accommodate public demands is required for the installation of water pipelines, natural gas lines, electric cables, and optical fibers. The soils extracted from these trenches always have substantial environmental and economic consequences, as these soils are frequently regarded as waste due to their poor engineering properties. As a result, a suitable location and method for disposing these excavated soils must be found, and this procedure is exceedingly costly, time consuming, and environmentally unfriendly. It is far more efficient to reuse these excavated soils for refilling the same trenches. This study is a part of a French national project. The national project aims to dig 5 to 25 cm wide trenches to install public utilities and to refill them using the same excavated material in the form of self-compacting mortar. The goal of this research is to determine the best ecofriendly binder for the soil excavated from various sites by conducting laboratory-scale physio-chemical and mechanical testing. This study examined the unconfined compressive strength (UCS) assessed by both destructive and non-destructive (ultrasonic) testing methods. By utilizing low CO2-emitting ecofriendly binders incorporating industrial byproducts (fly ash and GGBS), this work has broadened the possibility of reusing trench cuttings to refill the same trenches.

Measured and modeled maize and soybean growth and water use on pipeline disturbed land

Quantifying the impacts of soil disturbance on crop yield after installing an underground pipeline is essential for implementing effective mitigation plans and land restoration guidelines in agricultural systems. The objective of this study was to model maize and soybean yields on disturbed (subsurface pipeline installation areas) and adjacent undisturbed (control) land areas. Field observations and simulation results depicted the negative impacts of soil disturbance on soil physical, chemical, and hydrological properties. Grain yield and aboveground biomass losses up to 27% were observed in the pipeline disturbed area, where the soil profile had 15% lower plant-available water retention capacity than the undisturbed soil. APSIM was parameterized using two years (2019 and 2020) of in-season crop growth observations from a soybean-maize rotation system. Simulation of yield production was further evaluated against independent data from 2017 to 2018. The overall model performance was assessed using the index of modeling efficiency (EF). The model was effective in simulating aboveground biomass (EF disturbed-undisturbed: 0.96–0.98), grain yield (EF disturbed-undisturbed: 0.91–0.96), and soil water content in the 0–450 mm soil layer (EF disturbed-undisturbed: 0.84–0.86) for the parameterization dataset. Furthermore, the EF values for simulations of the independent yield data were also satisfactory (EF of 0.98 and 0.97 for disturbed and undisturbed soils, respectively). Soil disturbance reduced water use efficiency (WUE) by 25% and 30% in soybean and maize, respectively. This study indicated the suitability of using APSIM for simulating crop growth and yield production in the highly disturbed pipeline installation area.

New Methods for Predicting Strain Demand of Arctic Gas Pipelines across Permafrost under Frost Heave Displacement

With increasing gas resource development in the Arctic region, gas pipeline installations in permafrost regions are becoming important. Frost heave of pipeline foundation soils may occur when a chilled gas pipeline passes through unfrozen areas with frost-susceptible soils. The stress and strain behaviors caused by the differential frost heave will directly affect the safety of the pipeline. A nonlinear finite element model (FEM) computing the mechanical responses of the buried gas pipeline subjected to frost heave load was established and successfully validated with the results of a large-scale indoor pipe-soil interaction experiment carried out in Caen in France. Utilizing C# language and object-oriented visual programming techniques, a new customized parametric strain calculation software was developed. The effects of pipe diameter, pipe wall thickness, pipe internal pressure, and peak soil resistance on the longitudinal strain of X60, X70, and X80 steel pipes have been investigated quantitatively. For the first time, a fitting semiempirical equation and trained backpropagation neural network (BPNN) for predicting pipeline strain demand subjected to frost heave load were proposed based on 2688 groups of FEM results. The comparison results have proved their high accuracy and lower running time cost. The proposed new methods can be applied in the strain-based pipeline design and safety evaluation of pipelines in service. It is in the hope of supplementing existing theory and identifying new approaches for arctic gas pipeline installations.

Historical geomorphological adjustments of an Upper Rhine sub-tributary over the two last centuries (

Reconstructing evolutionary trajectories of river systems gives valuable insights into the main drivers (i.e. hydro-climatic versus anthropogenic) of their historical morphodynamics. Understanding past and modern adjustments of hydrosystems is therefore a key for appropriate sustainable management schemes. In this respect, the historical evolution (~150 years) of a 6 km dynamic reach of an Upper Rhine sub-tributary, the Bruche River, is thoroughly studied using a wide array of planimetric and topographic data (ancient maps and longitudinal profile, orthophotos, LiDAR). The primary aim is to precisely quantify the lateral and vertical mobility, taking uncertainties into account. Lateral mobility is studied using a specifically designed indicator, the Aggregated Migration rate Index (AMI), which enables precise assessment of planform changes in m.yr-1 on elementary sub-reaches (~100 m). A twofold decrease in mean lateral mobility in the mid-20th century, most probably related to functional channel modifications associated with the installation of an underground pipeline, represents the most striking result. Vertical mobility is analysed through the comparison of diachronic LiDAR data (decadal timescale) and historical archive (secular timescale). From the mid-20th century onwards, an unexpected general aggradation of the riverbed (~0.6 m) has occurred, for which several explanations are discussed (i.e. bank erosion, deforestation, sediment release following weir lowering), though remaining speculative. Overall, our results show that historical geomorphological adjustments are primarily controlled by various anthropogenic factors. As the Bruche hosts one of the highest concentrations of spawning beds of emblematic fish species in the French Upper Rhine, this study lays the foundation for future restoration strategies.

Short-term dynamics and long-term relationship between natural gas consumption and economic growth in Nigeria: an ARDL approach with breaks.

This paper investigates the short-term dynamics as well as the long-term relationship between natural gas consumption and economic growth in Nigeria, taking breaks into account. The techniques employed include Shahbaz-Omay-Roubaud unit root test with sharp and smooth breaks and autoregressive distributed lag (ARDL) model with breaks. The results revealed that natural gas consumption is positively related to growth both in the short-term and long-term but only significant in the latter. However, there is evidence of bidirectional causality in the long-term and unidirectional causality in the short-term, from growth to natural gas consumption. The implication of the findings is that natural gas is a contributing factor to the growth of the Nigerian economy, and any energy policy aimed at increasing the consumption of natural gas could lead to the increase in economic growth and that Nigerian authorities could adopt energy conservation policies in the short-term so as to take the issue of global warming into consideration. Therefore, the paper recommends stepping up efforts to increase natural gas consumption by building more gas storage facilities, pipeline installations, exploring alternative energy sources, raising awareness/enlightenment about the uses of natural gas, suitability in its use, economic and environmental benefits of its use, ensuring its affordable availability, and beeping up security against pipelines vandalization. Moreover, in the short-term, the country could enact energy conservation policies to combat global warming.

Temperature, season, and latitude influence development-related phenotypes of Philippine Aedes aegypti (Linnaeus): Implications for dengue control amidst global warming

BackgroundDengue is endemic in the Philippines. Aedes aegypti is the primary vector. This study aimed to determine the hatching behavior and viability of Ae. aegypti first-generation (F1) eggs when exposed to temperature and photoperiod regimes under laboratory conditions.MethodsParental eggs were collected from selected highland and lowland sites in the Philippine big islands (Luzon, Visayas, and Mindanao) during the wet (2017–2018) and dry (2018) seasons. F1 egg cohorts were exposed separately in environmental chambers at 18, 25, and 38 °C with respective photoperiods for 6 weeks. Phenotypes (percent pharate larvae [PPL], hatch rates [HRs], and reproductive outputs [ROs]) were determined.ResultsResults of multivariate analyses of variance (MANOVA) between seasons showed significant main effects of temperature, season, and big island on all phenotypes across all sites. Significant interaction effects between seasons on all phenotypes across sites were shown between or among (1) season and big island, (2) season and temperature, (3) big island and temperature, (4) season, big island, and temperature, (5) big island, altitude, and temperature, and (6) season, big island, altitude, and temperature. Factors associated with the big islands might include their ecology, available breeding sites, and day lengths due to latitudinal differences, although they were not measured in the field. MANOVA results within each season on all phenotypes across sites showed (1) significant main effects of big island and temperature, and (2) significant interaction effects between big island and temperature within the wet season and (3) between temperature and photoperiod within the dry season. PPL were highest at 18 °C and were formed even at 38 °C in both seasons. Pharate larvae might play an adaptive role in global warming, expanded distribution to highlands, and preponderance to transmit human diseases. HRs in both seasons were highest at 25 °C and lowest at 38 °C. ROs were highest at 25 °C in the wet season and at 18 °C in the dry season.ConclusionsTemperature and latitude of Philippine big islands influenced the development-related phenotypes of Ae. aegypti in both seasons. The two seasons influenced the phenotypes and their interaction effects with big island and/or temperature and/or altitude. Recommendations include year-round enhanced 4S control strategies for mosquito vectors and water pipeline installation in rural highlands.Graphical

Analysis Of The Installation Of Subsea Pipelines To Support The Need For Clean Water In Supporting Tourism Development On Kayangan Island

Inclusive access to water is very important for the tourism sector to maintain a good reputation among tourists and the social license of the local community to operate. While all stakeholders or stakeholders expect the success of tourism which contributes to economic improvement, community welfare, human resource development, and improvement of public health and the environment, tourism activities on Kayangan Island need clean water for their development. Considering that the island is one of the favourite tourist destinations and is growing quite rapidly at this time, there is no effective source of clean water available on the island. Therefore, it can be attempted to provide clean water by using subsea pipes sourced from PDAM Makassar. According to observations from various aspects, the pipe will cross the ocean with a span of ±1500 meters by flowing water with a discharge of 10 lt/s using HDPE pipes with a diameter of 140mm PE100, PN 16 according to SNI standards. For a fairly good security system, the jet pump and the pipe will be tied to a 110 mm diameter stainless steel sling bridge. In addition, at every 6 meters distance, the pipe bridge slings are fitted with ballast loads with hanging slings. In this study, the installation of subsea pipelines requires a variety of supporting equipment and also a complicated implementation, but it is can be carried out considering this needs to be done to support the need for clean water on Kayangan Island to support tourism development.

Analysis Of The Installation Of Subsea Pipelines To Support The Need For Clean Water In Supporting Tourism Development On Kayangan Island

Inclusive access to water is very important for the tourism sector to maintain a good reputation among tourists and the social license of the local community to operate. While all stakeholders or stakeholders expect the success of tourism which contributes to economic improvement, community welfare, human resource development, and improvement of public health and the environment, tourism activities on Kayangan Island need clean water for their development. Considering that the island is one of the favourite tourist destinations and is growing quite rapidly at this time, there is no effective source of clean water available on the island. Therefore, it can be attempted to provide clean water by using subsea pipes sourced from PDAM Makassar. According to observations from various aspects, the pipe will cross the ocean with a span of ±1500 meters by flowing water with a discharge of 10 lt/s using HDPE pipes with a diameter of 140mm PE100, PN 16 according to SNI standards. For a fairly good security system, the jet pump and the pipe will be tied to a 110 mm diameter stainless steel sling bridge. In addition, at every 6 meters distance, the pipe bridge slings are fitted with ballast loads with hanging slings. In this study, the installation of subsea pipelines requires a variety of supporting equipment and also a complicated implementation, but it is can be carried out considering this needs to be done to support the need for clean water on Kayangan Island to support tourism development.

Strategic approaches to sediment management for restoration of a deltaic plain

Sediment resources are essential to fulfill the State of Louisiana’s commitment to implement a Coastal Master Plan (CMP) to mitigate its chronic land loss, protect more than 2 million people who live in the coastal zone, and to save Louisiana’s rapidly disappearing complex and fragile ecosystem. With increasing rates of sea level rise and increased storm intensities along with continuing subsidence, the future quantity of sediment needed for ecosystem restoration will significantly increase, and at the same time, the accessibility to the sediment resources will become much more technologically challenging and cost prohibitive. These devastating environmental circumstances will compound the complexities of a sustainable ecosystem restoration in coastal Louisiana. Restoration projects must be robust enough (using adequate compatible sediment) to survive future environmental scenarios while the quantity of actively captured sediment resources available for critical restoration projects is likely to decrease, rendering the dredging and transporting of these sediment resources increasingly difficult and costly. These challenges will be an opportunity for Louisiana to utilize more sustainable, passively captured sediment (i.e. using large sediment diversions from the Mississippi River) to help offset limitations concerning actively harvesting sediment and to build and sustain wetlands in coastal Louisiana. Although any large-scale and meaningful restoration of the Louisiana coastal plain must involve sediments from the Mississippi River, the scope of this paper is restricted to offshore sediment resources. A strategic approach to optimize utilization of sediment resources includes minimizing handling and transport costs by first locating potential sediment sources and then identifying the most cost-effective way of using that sediment resource for restoration. The project cost and its success are defined by the sediment selection process. Thus, it is suggested that improvements in planning and management of multiple-use conflicts be based on regional understandings of sediment resources for an approach that maximizes benefits. The Louisiana Sediment Management Plan (LASMP) was conceptualized and formulated to improve planning and coordination of sediment utilization in Louisiana. This plan has evolved and has been adaptively managed in the absence of any prototype. Restoration activities are further complicated by competing interests and multiple uses of limited sediment resources. To maximize the availability of offshore sediment, the state is collaborating with the Bureau of Ocean Energy Management (BOEM) and engaging with other stakeholders in deciding the fate of decommissioned pipelines and to strategically plan the installation of new pipelines in offshore areas identified as significant sediment resources with the intent of protecting identified sediment resources for future use. Future offshore wind-farms may pose new challenges but simultaneously offer opportunities for conflict resolution via stakeholder engagement. For the past two decades the State of Louisiana/Coastal Protection and Restoration Authority (CPRA) of Louisiana has developed a considerable institutional knowledge base and expertise and improved the art and science of sediment management. A robust process has been adaptively developed with interagency collaboration and coordination to resolve conflicts/issues concerning obstacles to resource access. LASMP is not only a template for sediment management for coastal restoration, but also provides guidance for stakeholder engagement and conflict resolution for competing needs of seafloor resources especially in Northern Gulf of Mexico (NGOM).

Vector form intrinsic finite element analysis of deepwater J-laying pipelines on sloping seabed

The dynamic responses of offshore pipelines induced by J-laying effects are remarkable and dominate the pipeline design and installation feasibility in practice. Most previous studies have focused on the analysis of pipeline installation on the horizontal seabed. In this paper, an extended J-lay model based on the vector mechanics principle is developed to investigate dynamic behaviors of laying pipelines on the sloping seabed. Two representative seabed slope types are taken into account involving the positive and negative slopes. The laying pipeline is divided into a sequence of mass particles linked by massless elements, and the deformations of the elements and the rotations of the particles are calculated to obtain the internal forces. The explicit central difference technique is applied to solve the movement governing equations of pipeline particles by program coding. Two illustrative cases of a 12-inch pipeline being laid separately from the horizontal seabed to the positive and negative sloping seabed are simulated under a random sea state. The influences of seabed slope type and angle on pipeline responses are estimated quantitatively. Significant differences of pipeline behaviors between the positive and negative sloping seabed are observed, which offer very intuitive evidences of seabed slope effects concerning deepwater J-laying pipelines.