North American Special - Trenchless International

More documents

Recommendations

Info

Locating laterals in Toronto Benko Sewer Services of Ontario uses four IBAK Lateral Launch Systems (LISY) in order to maintain essential services in the city of Toronto, Canada. A guide to manual coating application products anD services April 2009 - Trenchless International Benko, a division of Badger Daylighting, is a multi-disciplinary company that specialises in CCTV inspections, maintenance and flushing\cleaning of sewers, catch basin cleaning, smoke and air testing, and hydro-excavating. For the past 15 years, Benko has serviced and supported customers from all regions of Ontario. Benko uses only industry leading products from the most respected manufacturers in the world today, offering diverse applications to meet the needs of both private and municipal clients. The IBAK - LISY lateral launch system was introduced in 1993. The first of its kind, the LISY has evolved throughout the years and still provides users with unparalleled control, capability and picture quality. Over the past year, the company has increased its existing fleet of CCTV trucks by acquiring four IBAK lateral launch units to complement and maintain essential wastewater services. The trucks have been used to carry out lateral launch contracts in both the municipal and private sectors and have to date pushed over three thousand lateral launches as well as increasing the capacity for regular mainline contracts. Benko has had great success with these units in respect to productivity, reliability and quality of the end product. The picture quality is constantly noticed by clients and maintains a consistently high quality in any pipe size. The operating platform for the CCTV operators is quite different from the rest of the fleet, but training has been of minimal effort due to the user-friendly nature of the control system. The company focuses on quality equipment, such as the Badger Hydrovac units, and sees this as being the key to achieving success in the industry. The company believes that IBAK has been the equivalent on the CCTV side of the business and has given the ability to mix high quality equipment with high quality operators to achieve a superior service. Benko has been employed on a contract within the city of Toronto, which requires locating the depth and line of the sewer connections up to the building line. The advantage of this method is that there is no intrusion to residential property (in order to remove toilets) to achieve the same location results. The main contract being carried out at present is lateral locating using the IBAK - LISY. The trucks are pushing lateral launches every day. A Benko spokesperson said “we have faced many different scenarios with the condition, line, material of the pipe, but the IBAK Lisy has been consistent in giving us the results we are looking for. One area in particular would be where there is a ‘Y’connection within the sewer lateral. “We are able to push both ways through the ‘Y’ by using the pan and tilt motion and the guide rod to direct us into each line as required.” The spokesperson said another key advantage with the system has been the capability of carrying out a manline ‘manhole to manhole’ run and to seamlessly carry out required lateral launches along the line using the same camera and data collection software without the need to produce separate video files and reports. A truck with IBAK - LISY on board. RapidView IBAK North America distributes IBAK products through a dealer network in the United States, Canada and the Caribbean Islands. The rehabilitation of pipes damaged by corrosion has resulted in the creation of innovative and effective solutions. The following provides a ‘how to’ guide for the manual application of mortar coatings. The coating of drinking water pipes has been offered within Germany since 1970. Cement mortar coatings, as per DWGW W 343, DIN 2880, DIN 2614 and EN 805, are carried out in situ on pipes from DN 80 diameter upwards. The centrifugal spray technique is a clear favourite application method. Sewer pipes have been coated with mortar in Germany since 1982. The applications methods are: 1. Manually applied coating 2. Wet spray coating 3. Centrifugal spray coating 4. Displacement process Shafts and other installations in the German public drainage system have also been coated with mortars since 1982. Manually applied and wet spray coatings were the predominant methods, however the centrifugal spray M-coating process has gained more popularity recently. Manual Coating Equipment: Mortar mixing container, bucket, two-paddle mixer, trowel, steel float, sponge board, coarse sponge, graduated water container, brush or soft broom Applying the bond layer: The first step is to create a bond layer using the renovation mortar. The grout needs to be mixed to a consistency between soft and plastic and then brushed onto the prepared substrate. The bond layer should be approximately 1-2 mm thick. If the substrate shows signs of damage or cavities, these must be filled in with mortar. Mixing the pipe renovation mortar: The appropriate ERGELIT-KS mortars are mixed according to their particular instruction sheet. Always take care to put the water into the mixing receptacle first. The amount of water, calculated as a percentage in relation to the dry weight of the mortar must be exact in order to guarantee the desired water-solid ratio of 0.4 or less. The water-solid ratio is usually provided as this is more practical for mixing dry mortars on site. It is also extremely important to mix the mortar for the recommended time. Coating: The mortar coating is applied by trowel and float, wet-onwet, to the bond layer applied previously. Using the trowel to apply the mortar, as is done with ordinary cement mortars, is difficult in this case because of the high adhesion factor and is not advisable. However, there are often occasions when technically there is no alternative. As a rule, several wet-on-wet applications are required depending on the depth desired. It is essential that the surface be lightly roughened between coats with a sponge or sponge board to ensure the application of the next coat. The surface of the final coat is smoothed with a damp brush in order to prevent water and air becoming trapped during the final steel coat smoothing. When repairing damage caused by biogenic sulphuric acid, if using ERGELIT-KS 2b as coating mortar, the fresh mortar’s high thixotropy must be taken into account. This means that the fresh mortar will stiffen in the mixing container after about 5-10 minutes if mixing is interrupted. If this occurs, the mortar can be re-mixed for 20-30 minutes to recover its original consistency. In order to speed up the setting time, some mortars can be modified by the use of compatible accelerators, however the manufacturer should be consulted. Ambient temperature influences working time and must be observed. Working times for the different mortars can be obtained from technical data sheets available from the manufacturer. As manual coating has little impact energy, it is generally considered to be a top surface coating technique. In the past manual coating was the most popular technique. In the future it is anticipated that the wet-spray technique will be used for larger and irregularly shaped installations. products and services April 2009 - Trenchless International 34 35
Risky business by Roderick Lovely asset management April 2009 - Trenchless International 1% 20% 36% 3% Total miles of pipe by material 9% 52% 3% Managing assets in Las Vegas Trenchless Technology contributes substantially to asset management across the world. Charles Scott from the Las Vegas Valley Water Department spoke with Trenchless International about their asset management program. Las Vegas is the most populous city in the USA state of Nevada. The Las Vegas Valley, a 600 square mile (1600 km²) basin and surrounding area, is part of Clark County in southern Nevada. Mr Scott says the Las Vegas Valley Water District (LVVWD) is responsible for over 4,500 miles of pipe in Las Vegas and unincorporated Clark County. Mr Scott says “We also manage over 100 miles of pipe in separate small water systems in the communities of Jean, Searchlight, Blue Diamond, Laughlin, and Kyle canyon.” The breakdown of total miles of pipe by material is shown below. The largest steel pipe, including mortar lined steel pipe, bar wrapped steel pipe and pre-tensioned wire wrapped pipe is 102 inches in diameter. Most pipe in this class ranges from 24-48 inches in diameter. PVC pipe ranges from 4 inches up to 42 inches and ACP from 4 inches to 60 inches. Most PVC and ACP pipe are from 6 – 8 inches. Mr Scott says that because of Las Vegas’ phenomenal population growth over the past ten years, the average age of all pipes in the distribution system is only about 18 years. The average age for PVC pipe is eight years compared to ACP, which has an average age of between 29 and 34 years. ACP has the highest break rate per mile compared with all other pipe materials. When asked what portion of assets the LVVWD inspects every year, Mr Scott says they are currently focusing assessment activities on ACP and steel pipe. “For ACP, our assessments are prioritised based on our CARE-W [computer aided rehabilitation of water networks] model that ranks pipe in terms of risk of failure – based on statistical failure modelling and hydraulic criticality – based on hydraulic modelling tool re-net. Asbestos cement Cast Iron Unknown Ductile iron PVC Polyethylene Mortar lined steel “We also try to employ the best available technology and use non-invasive techniques as much as possible.” “Other criteria such as impact to customers, potential damage to rods and types of customer served are also important considerations,” says Mr Scott. For steel, the LVVWD assessments are prioritised based on corrosion potential information collected from the Cathodic Protection system, as well as the potential consequences of failure, impact to customers and break history. “We have just this year implemented our CARE-W model, and have started a full-blown assessment program,” says Mr Scott. “This year we will assess approximately 10 miles of ACP, and from 10 up to 15 miles of steel pipe.” Mr Scott says that the total amount of ACP to be assessed each year will vary depending on the output of the model. The LVVWD plans on assessing approximately 20 miles of steel pipe annually. Trenchless International asked if the District has adequate funding to conduct the inspection and repair programs. Mr Scott answered “Funding is a challenge for all utilities, this is why we are careful to assess only those pipes at the most risk.” The LVVWD is just beginning to investigate the advantages of Trenchless Technology following a successful CIPP project. The District will be evaluating the applicability of Trenchless solutions on a case by case basis. Quantifying risk is fundamental to any physical asset management program, the following article presents how this information can be obtained and used to assess risk. Water and wastewater infrastructure managers make decisions every day that are aimed at reducing the risk of costly failures. For most, the decision process is ingrained, based on years of experience and knowledge in system management. But over time systems change, people retire, the knowledge base is lost, assets age, and the probability of costly failures increases. This is especially true in developed countries where underground utilities have been in place for over a hundred years, and the people who manage them are nearing retirement. As a new generation of managers emerges, they are being asked to manage assets that are nearing the end of their useful life with fewer resources, and tougher regulatory requirements, such as California’s Sanitary Sewer Management Plan, or SSMP. To cope with these challenges, savvy managers are turning to computer applications with physical asset management (PAM) features to allocate limited resources more strategically. Fundamental to PAM is prioritisation of assets based on a risk model. At a minimum, this involves knowing how assets might fail and what would happen if a failure were to occur. In PAM we define ‘how assets might fail’ as the probability of failure (PoF) and ‘what would happen a failure were to occur’ as the consequence of failure (CoF). Risk is simply the product the PoF and CoF: Risk = PoF x CoF. Probability of failure To determine the PoF of any asset we must first determine how it may fail in terms of failure modes. When we categorise how an asset may fail there are at least four failure modes to consider that are common to all assets. Condition Condition may be put in terms of a Condition Rating by quantifying the number and extents of defects, or by direct measures such as a vibration analysis. It may be helpful to measure condition in both O&M Condition and Physical Condition. O&M Condition can be addressed through tasks such as cleaning and lubrication, while Physical Condition may call for capital remedies such as overhaul and replacement. Probability What it means 100 per cent Failure likely to occur within a year 90 90 per cent chance of Failure in any year – Failure likely within 2 years 50 50 per cent chance of Failure within any year 20 20 per cent chance of Failure within any year 10 2 10 per cent chance of Failure within any year – 90 per cent chance it won’t 2 per cent chance of Failure within any year - 98 per cent chance it won’t Age For age to have meaning we must first determine the life expectancy of any asset. Life expectancy can be influenced by many factors such as the surrounding environment, construction material, and installation techniques. Although age is often a good predictor of condition, an asset that appears to be in good condition may start to deteriorate rapidly or suddenly fail as it approaches the end of its useful life. Knowing how close your assets are to the end of their life expectancy may influence how often you inspect them or how you develop a replacement strategy to avoid costly failures. Capacity Does the demand placed on the asset exceed its original design capacity Influences such as population increases can certainly affect capacity. You must know what the demands are on your assets to measure capacity. Bear in mind that assets that are substantially underutilised could also lead to a higher PoF. Level of Service Perhaps the asset was put into place before new regulatory requirements were enacted. Stakeholder expectations for issues such as noise, odour, and safety may be more stringent now. Or it may be that newer alternatives have been developed that reduce the cost of operation to the point that it will be less costly to replace than to continue to operate. Establishing acceptable levels of service will help you make these determinations. Your actual list of failure modes will vary depending on the asset types that you are rating, but they will all most likely fall into one of these four categories. As you develop your criteria, take into account that ‘failure’ does not always mean a catastrophic failure, but it does mean that continuing to operate the asset without taking action will be more costly than doing something about it. Quantifying probability of failure When it comes to age, we humans inherently know that the probability of end of life increases as we grow older, and that probability increases at an accelerating rate. However, we have no way of determining precisely when the end will occur. The same is true for physical assets. But what we can do is apply a probability based on experience and historical data when available. Below is a sample table that shows how one might interpret levels of probability in a risk model. For the failure mode of age, the graph for static assets such as pipes and manholes where failure rarely occurs early in life can be illustrated in an age based curve. Mechanical and electrical assets are more prone to failures early in life and hence the probability of failure curve associated with these types of assets is often referred to as a ‘bathtub’ curve. If reliable historical data is available then the PoF should be based on the percentage of failures actually experienced. Similar curves can be created for other failure modes such as capacity where asset management April 2009 - Trenchless International 36 37
Page 1 and 2: In this issue | Canada | USA | Japa
Page 3 and 4: Dec Downey Istt Chairman Trenchless
Page 5 and 6: EXECUTIVE DIRECTOR'S REPORT John He
Page 7 and 8: Pipes & People Prime Horizontal pip
Page 9 and 10: Trenchless in Toronto The 2009 Inte
Page 11 and 12: Events ISTT International No Dig 20
Page 13 and 14: projects April 2009 - Trenchless In
Page 15 and 16: Insertion of the liner takes about
Page 17 and 18: Alleviating flooding in Ashbourne S
Page 19: obotics April 2009 - Trenchless Int
Page 23 and 24: Deterioration Factors Distress Indi
Page 25 and 26: environment Supplying the community
Page 27 and 28: Record SWP down under Interflow, an
Page 29 and 30: north america April 2009 - Trenchle
Page 31 and 32: north america is a biaxial stress,
Page 33 and 34: disc cutter heads to work through t
Page 35 and 36: “We had a very tight window to ge
Page 37 and 38: Undersea HDD rescue in Saudi Arabia
Page 39 and 40: ADVERTISERS INDEX SUBSCRIPTION FORM

North American Special - Trenchless International

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?