Markov and Neural Network Models for Prediction of Structural Deterioration of Stormwater Pipe Assets

Storm-water pipe networks in Australia are designed to convey water from rainfall and surface runoff. They do not transport sewerage. Their structural deterioration is progressive with aging and will eventually cause pipe collapse with consequences of service interruption. Predicting structural condition of pipes provides vital information for asset management to prevent unexpected failures and to extend service life. This study focused on predicting the structural condition of storm-water pipes with two objectives. The first objective is the prediction of structural condition changes of the whole network of storm-water pipes by a Markov model at different times during their service life. This information can be used for planning annual budget and estimating the useful life of pipe assets. The second objective is the prediction of structural condition of any particular pipe by a neural network model. This knowledge is valuable in identifying pipes that are in poor condition for repair actions. A case study with closed circuit television inspection snapshot data was used to demonstrate the applicability of these two models

Risk of root intrusion by tree and shrub species into sewer pipes in Swedish urban areas

Blockages in sewer pipes caused by roots are very common and several tree and shrub species are reported to be particularly likely to cause root intrusion. This study examined the relative ability of roots of different species to intrude into urban sewer pipes. Data on root-intruded pipes and the woody plants surrounding these pipes were collected from two Swedish cities, Malmö and Skövde. Plant material, location data and closed-circuit television (CCTV) inspections on root-intruded pipes with a total length of 33.7 km, containing 2180 different points of root intrusion, were examined. An inventory of 4107 woody plants was compiled. The results showed that broad-leaved trees dominated as a cause of root intrusion, but that conifers and a number of shrubs, e.g. the genera Ligustrum, Spiraea and Syringa, were also likely to have caused root intrusion. Malus floribunda Van Houtte was found to have the highest mean share of root intrusions per estimated number of pipe joints when all joints and all root intrusions within a 10 m radius from trees were calculated (0.694, maximum number of intrusions per joint 1.0), while Populus canadensis ‘Robusta’ Moench had the second highest, with 0.456 intrusions per estimated joint. However, other Malus and Populus species and cultivars had a much lower mean share of root intrusions. Most species seemed capable of causing root intrusion, and not only species of the genera Populus and Salix that were previously seen as the species most likely to cause damage to stormwater and sewer systems. There were differences in the frequency of joint intrusion by roots of different species, but the reasons for these differences were not identified and further research in the area is needed

Developed Pipe Bursting Specifications Using High Density Poly Ethylene (HDPE)

Pipe bursting is a trenchless method for replacing old deteriorated or under sized pipe by fracturing or splitting. Earlier published pipe bursting specifications do not completely cover the current state of the art and without proper allocation of risks. Specifications are set of written instructions given by the owner to the contractor. The developed Pipe Bursting specification with HDPE will help the owners, contractor, and engineers to carry out a successful burst timely and economically. In this research study, sixteen specifications from various sources were collected. Various agreements and disagreements among these specifications were identified, analyzed, and considered while developing the draft specification reflecting the current state of art. Based on these findings, the following topics are identified for the specification and instructions are given accordingly: General, Definitions, Reference Standards, Qualifications of the Contractor, Submittals, Pipe Fusion, Methods of Pipe Bursting, Testing and Inspection, Locating Utilities and Service Connections, Bypassing the flow, Traffic Control Plans, Service Reconnection, and Site Restoration. The proposed draft specification adopted the statements agreed upon by the majority of the specifications and conformity with the current state of the art. Peer reviewing by industry experts can further develop the draft specifications

Automated Defect Detection Tool For Sewer Pipelines

In sewer networks, the economic effects and costs that result from a pipeline break are rising sharply. In Qatar, majority of the sewer network pipelines were installed in the last 20 years and are currently in poor condition and constantly deteriorating. As a result, there is huge demand for inspection and rehabilitation of sewer pipelines. In addition to being inaccurate, current Practices of sewer pipelines inspection are time consuming and may not keep up with the deterioration rate of the pipelines. Consequently, this research aims to develop an automated tool to detect different defects such as cracks, deformation, settled deposits and joint displacement in sewer pipelines. The automated approach is dependent upon using image-processing techniques and several mathematical formulas to analyze output data from CCTV camera photos. Given that one inspection session can result in hundreds of CCTV Camera footage, introducing an automated tool would help yield faster results. Additionally, given the subjective nature of most defects, it will result in more systematic results since the current method rely heavily on the operator's experience. The automated tool was able to successfully detect cracks, displaced joints, ovality and settled deposits in pipelines using CCTV Camera inspection output footage. Using two different data sets, the constructed Matlab code could successfully differentiate between cracks and displaced joints with an overall crack detection success rate of 84% and an overall displaced joint detection rate of 94%. The code was also able to efficiently detect settled deposits in the pipelines with a detection rate of 90%. In addition, the automated ovality detection resulted in 100% compatibility with the manual circularity detection

Kidnapped laser-scanner for evaluation of RFEC tool

© 2015 IEEE. An algorithm is proposed for matching data from different sensing modalities. The problem is formalised as a kidnapped robot problem, where Bayesian fusion is used to find the most likely location where both modalities agree. The key idea of our algorithm is to model the correlation between the two modalities as a likelihood used to update a location prior. Data, in this case, is represented as 2.5D thickness maps from a laser scanner and a Remote Field Eddy Current (RFEC) tool, used in non-destructive testing to assess the condition of infrastructures. The laser data is limited, while RFEC data is continuous. Given some prior in location, the aim is to find the 2.5D thickness map from the laser that corresponds to the RFEC data, which should be noted is highly noisy. Real data from CCTV inspections of water pipes are used to validate the proposed approach

Avaliação da condição estrutural do sistema de drenagem de águas residuais com base em análise de risco e inspeção CCTV

A razão para avaliar a condição dos coletores do sistema de drenagem de águas residuais é a prevenção da falha, a fim de evitar situações de emergência. Um dos desafios destes sistemas está no facto dos mesmos estarem enterrados, sendo a única forma de conhecer e avaliar o seu estado a realização de inspeções com recurso à tecnologia Closed-Circuit Television (CCTV). A metodologia desenvolvida efetua a previsão de deterioração dos ativos ao longo do tempo e tem por base os resultados de inspeção CCTV e as características dos coletores inspecionados. Se existirem dados suficientes para apoiar esta metodologia, as intervenções poderão ser realizadas antes do sistema entrar num nível inaceitável de serviço. O objetivo deste trabalho passa por uma recolha de dados contínua, de forma a poder-se analisar e avaliar essa informação ao longo do tempo, validando assim o mapa de riscos desenvolvido. A metodologia desenvolvida foi aplicada à Infraquinta e os resultados mostram uma forte concordância entre os critérios de risco e a inspeção CCTV realizada.info:eu-repo/semantics/publishedVersio

The real issues with in-ground SUDS in Scotland

The aim of this research was to produce enhanced detailing and improved operation of in-ground SUDS. Data from on-site monitoring at three filter drain and three infiltration trench systems were analysed and the results were combined with information gathered from 40 assessments of in-situ systems in Eastern Scotland. Current findings showed that almost 50% of all systems were found to be unsatisfactory and more than half of these were rated as having failed. 36% provided fair and 16%, good performance. Only one system was considered to be performing excellently. Several reasons were identified for the poor performance. The principal cause of problems was runoff from unstabilised areas or construction runoff, which was found to be affecting the systems’ longevity. Almost 30% of all sites were affected by construction runoff. Another major problem was related to system maintenance since maintenance programs were generally not in place. This study has shown that regular maintenance is vital for the longevity of in-ground SUDS

Development of Renovation Techniques for Medium and Large Diameter Water Transmission Pipes

Smart lining System was developed to restore and improve water quality, hydraulic, and structural function of water large transmission pipes through the construction of the high quality lining in the study. Smart lining System consists of smart cleaning, smart spray-on lining, and smart CIPP2+. Smart cleaning is the pre-process of lining process, and could ensure SSPC SP-10 and surface roughness 50 μm(Rz) as the quality of surface preparation for the lining by removing effectively deposited slime, residual lining, tuberculation, graphitization of pipe wall with the high pressure water jet, mechanical scraper, and air spin-head blasting equipment step by step