The first ever Hobas pressure pipe

Transcription

1 THE HOBAS A PUBLICATION HIGHLIGHTING THE TECHNICAL AND PRACTICAL USES OF HOBAS PIPE Hobas Pipe USA, Inc. November 1998 MICROTUNNELED FORCE MAIN NEAR FLAWLESS PERFORMANCE The first ever Hobas pressure pipe installed by microtunneling (re mote-controlled jacking) is nearly complete with almost flawless performance in Orlando on the Bennett Rd. project. The new 36" diameter sewer force main includes over 4700 feet of 100 psi rated, 260 ton, centrifugal cast, fiberglass-reinforced polymer mortar (CCFRPM) pressure jacking pipes supplied in 20 foot sections, field assembled with flush FWC coupling joints. I N S I D E THE HOBAS Product Profile Sliplining Installations 2 Las Vegas Grows with Hobas Again 4 Trouble Free Rehabilitation 5 Hobas Microtunnel Saves Millions of $ 6 Conference Exhibits 8 Peak jacking loads did not exceed 120 tons. MICROTUNNELING CHEAPER The line also included 14,000 feet of PVC pipe, which was installed by open cut construction. However, due to interference from numerous other utilities, some adjacent wetlands, surface drainage ditches, crossing of route 436, heavy area traffic and a building in the 1000 ft. drive completed at 60 ton jacking load. right-of-way, a portion of the job was specified for microtunnel installation only. Not only did the trenchless construction method solve or avoid most of these conflicts, it was also substantially lower in cost versus open cut for this segment! (continued on page 7)

2 PRODUCT PROFILE SLIPLINING INSTALLATIONS - HOBAS PIPES ARE THE PREMIER PERFORMER INTRODUCTION Although the majority of Hobas pipes are installed by common open cut construction, these smooth wall, high strength pipes have earned their superior reputation and notoriety primarily due to their success in trenchless applications. The most popular of the trenchless installations is sliplining rehabilitation, where Hobas pipes are clearly the premier product. CHARACTERISTICS Description Generically, Hobas pipes are centrifugal-cast, fiberglass-reinforced, polymer mortar (CCFRPM). Scope * Diameters: 12" to 102" currently available. * Standard classes: - Stiffness: Most commonly 36 or 46 psi, although other values, higher or lower are available and are sometimes needed. - Pressure: Most applications are non-pressure, however, ratings for 50, 100, 150, 200 and 250 psi are available. * Section lengths: 20 ft. is standard, but 10, 6.5, 5, 4 and 2.5 ft. sections are used in curves or when small pits are necessary. * Joints: Several gasket-sealed, bell-spigot configurations are suitable based on fit and service pressure: - Non-pressure: Low-profile or flush (see figure). - Pressure: FWC coupling with overwrap (see figures). * Fittings: Although not used frequently in this construction method, a wide variety of mitered and molded fittings are available: Elbows Manholes Tees Wyes Reducers Laterals Nozzles Flanges Hobas pipes smooth interior surface has superior hydraulic characteristics. Reconnection of most lateral services is accomplished using Inserta- Tee fittings (up to 12"). APPLICATIONS Majority of applications are sanitary sewer interceptors, however, the pipes are also ideal for relining other services including storm drainage, industrial effluents, culverts and sometimes force mains. INSTALLATION Preparation of the existing (host) pipe For non-pressure services, the host pipe may be maintained in operation during the lining process. Obstructions such as roots, large joint offsets, rocks or other debris, etc. that would prevent passage or damage the liner pipe sections must be removed or repaired prior to installing the new pipe. Before starting the liner insertion, verify the existing pipe diameter is sufficient by pulling a mandrel through the line. Liner pipe insertion Access to the host pipe is normally achieved via a shaft constructed directly above the line. Liner pipes may be pushed or pulled (from the back end) into the existing line. The pipes must be inserted spigot end first with the bell end trailing. Frequently the leading pipe spigot end is protected by a nose piece designed to rideup and over offset joints and other minor inconsistencies or small debris in the invert. Distances lnsertion pushing distances may be limited by turns (PI s) in the host pipe. However, when the existing pipe alignment allows, push distances of 2000 ft. to 3000 ft. are routine and up to 5600 ft. have already been accomplished. Grouting Generally the annular space between the liner OD and host ID is filled with grout to provide support to the liner to resist external loads, to prevent water and soil from entering the annulus and to fix the liner pipe position. Maximum grouting pressure is a function of the liner stiffness, annulus size and flow conditions. Experience Over 500,000 ft. installed by sliplining by mid BENEFITS Hobas CCFRPM pipes provide many benefits to the user and installer. Some are applicable to any installation method and may be termed universal. Others are most significant and valuable specifically on trenchless installations such as sliplining. 2

3 PRODUCT PROFILE Universal Benefits Features Benefits Sliplining Benefits Features Benefits Inherent corrosion resistance Leak-free joints Push-together assembly Lightweight Resilient inner liner Mold smooth, consistent O.D. Smooth l.d. Long service life even in corrosive environments No add-on linings or coatings to install, inspect or maintain Hydraulics unchanged over time Zero infiltration lowers treatment costs No undermining of structures above No ground water pollution Pass tests easily; the first time Fast joining No welding required Less expensive handling equipment Excellent abrasion resistance High crack resistance Pipes may be cut anywhere and assembled with gasketed joints with only end chamfering preparation needed Superior hydraulic characteristics High flow capacity Significant energy savings in pumped systems Segmented pipes with gasketsealed joints Constant, smooth OD Solid wall with ideal density High compressive strength Lightweight High stiffness & flex strength Low profile wall Flush and low profile bell-spigot joints 26 diameters between 18" & 102" Superior hydraulic characteristics Small shafts Live insertion No by-pass pumping required Minimize surface disruption Lower push loads Longest push distances Fewer shafts required Highest reliability and safety margin Lowest installation cost Highest allowable grouting pressure High load & deep covers capability Pipes are rugged & durable Largest ID to fit most all lines Improve flow capacity after lining Joints with angular rotation capability Liner negotiates host alignment easily Some curves & Pl s may be lined CONCLUSION Specify and use Hobas centrifugal cast fiberglass-reinforced polymer mortar pipes on your next jacking project to experience and enjoy these many, unique, cost saving benefits. Low profile bell-spigot Flush bell-spigot. 3

4 LAS VEGAS GROWS WITH HOBAS AGAIN Hobas pipes safely withstand deep burials. Although over 1000 miles apart, Hobas Pipe USA, Inc. and Las Vegas have an important common trait; both are growing rapidly. Hobas sales in the U.S. have tripled in the last 5 years and Las Vegas has experienced explosive growth also. To maintain service, the utility infrastructure in the Las Vegas area has been continually expanded during the 80 s and 90 s. Hobas pipes have played a significant role having been utilized on several jobs. The recently completed West Russell Road Relief Sewer Phase 1 of the Clark County Sanitation District is one such project. This new interceptor, installed by open cut construction, included 2.5 miles of 36" and 42" Hobas centrifugally cast fiberglass-reinforced polymer mortar (CCFRPM) pipes. CHALLENGING CONDITIONS Due to low initial flows, project designer G. C. Wallace, Inc. of Las Vegas, needed pipes with corrosion resistance to septic conditions. Structural integrity was also critical because 90% of the pipes have over 20 feet of cover with a maximum of 27 feet. Additionally, most of the alignment is under roads which were unpaved during the construction. Finally, to protect the surroundings and minimize flows, no visible leaks were allowed and the lines had to pass an air test. These criteria led to the specification of SN 46 Hobas CCFRPM, RCP with 300 deg. PVC lining or RSC 160 HDPE pipes. TROUBLE-FREE & FAST Hobas pipes were selected by installer, Dow Industries of Las Vegas, primarily because of a lower installed cost. Even though this project was Dow s first using Hobas pipes, the job was virtually trouble-free and all of the pipes were installed in less than 4 months. Despite the deep cuts, typical daily production was over 200 feet. Dow particularly liked the tight, yet easy to assemble, push-together, gasket-sealed FWC coupling joints. Additionally, Dow was pleased by the ease and speed of field length adjustments. Since the FWC coupling seals directly on the molded pipe exterior surface, the pipes may be cut anywhere on the barrel and connected using the couplings with only an end chamfer required. HIGH PERFORMANCE The CCFRPM pipes were bedded in a dumped surround of 0.75" minus crushed rock. This burial and the pipes 46 psi stiffness combined to achieve a high quality installation. Not only did the entire line pass the 5% deflection requirement with no remedial work, all measurements taken revealed no deflections exceeding 1.5%. Better yet, 3.5 psi line air tests all also passed with no leakage at all! This performance is not unusual for Hobas installations and actually is a repeat of a previous Las Vegas project. With this 5th city of lights project successfully complete, Hobas is now preparing to deliver to Las Vegas over 3 miles of 54 and 66 pipes for another open cut interceptor, the Sandhill Relief Sewer. Field length adjustments are fast and easy due to the constant pipe OD and the FWC coupling. Handling is easy and inexpensive with rugged, yet lightweight Hobas pipes. 4

5 TROUBLE FREE REHABILITATION High performance, consistent Hobas centrifugal cast, fiberglass-reinforced polymer mortar (CCFRPM) pipes contributed to another trouble-free sliplining installation on the recently completed North Long Beach Trunk Sewer Section 1 Rehabilitation. This project, another in a long series for the County Sanitation Districts of Los Angeles County (LACSD), consisted of over 2 miles of existing deteriorated 30 RCP interceptor lined with 26" Hobas pipes. MANY SPECIFIC NEEDS Similar to many past LACSD rehab projects, this liner also had to be installed without by-pass pumping of the sewage flow. Additionally, a 46 psi minimum pipe stiffness was required to resist the maximum annular space grouting pressure of 12 psi. This pipe class had to be achieved with a maximum OD of 28" to enable a low-risk insertion fit and with a minimum ID of 26" to assure adequate flow recovery. As always, the new liner had to be resistant to future sulfide attack and the periodic caustic treatment program. Finally flush gasket-sealed bell-spigot joints were needed for quick assembly, leak-free performance and a smooth exterior surface. This combination of critical criteria again led LACSD engineers to specify only CCFRPM pipes. The Buntich crew celebrates inserting 2,000 ft. of liner (100 pipes) in just 6.5 hours. EASY INSERTION Due to 3 siphons and 2 significant Pl s in this otherwise straight section, contractor Mladen Buntich of Sunland, utilized 5 access pits to insert the mostly 20 foot long liner pipes. Push loads were low with a maximum of only 20 tons needed even on the longest drive of 2450 feet. Insertion was fast because of the push-together joints and Buntich s new pushing machine. The versatile, hydraulic powered, chain drive unit installed 100 pipes (2000 feet) in only 6.5 hours, a rate of less than 4 minutes per section! Despite this success, the most pleasing achievement may have been no damaged pipes! placed in 1 lift, completed the lining portion of the project. Final video revealed a tight, sound system installed trouble-free! Now with over two dozen projects completed utilizing over 120,000 feet of Hobas CCFRPM liner pipes, LACSD is continuing their interceptor rehabilitation program frequently using more of the same. Currently no less than 5 additional projects totaling over 20,000 feet of Hobas CCFRPM liner pipes are in various stages of production and construction. REPEAT SUCCESS Prior to grouting, the annular space was standpipe tested to the maximum grout pressure with no leaks detected in the liner pipes or joints. Annulus grouting, with an 80 pcf cellular foam mix Hobas flush gasket-sealed joints assemble quickly and insert easily. Inspectors witness fast lining process. Connection in the access pit of pipes pushed opposite directions is made using Hobas closure coupling. 5

6 HOBAS MICROTUNNEL SAVES MILLIONS OF DOLLARS Use of microtunneling and Hobas centrifugal cast, fiberglass-reinforced polymer mortar pipes on the Southeast Interceptor II project in Derby, Kansas reduced costs over 50% compared to conventional methods. Additionally, the trenchless installation pacified residents anger over the destruction of the environment and disruption of their community that occurred on phase 1 of this line built several years ago by open cut DEMANDING PERFORMANCE The new 36" line extends this sanitary sewer another 3000 feet and will service projected growth in the area for the next 40 years. Therefore, since flows will be low for several years, a corrosion resistant pipe was needed to withstand the septic conditions that are certain to occur. Further, with cover depths up to 44 feet beneath streets, a strong, structurally reliable pipe was a must. Finally, to control leakage, a 50 inch-gallon (gallons / inch of diameter / mile of line / day) infiltration test was included. To meet these requirements, project designers, Professional Engineering Consultants of Wichita, specified only CCFRPM or extra strength VCP pipes and gasket-sealed bell-spigot joints. Hobas pipes suitable for depths over 40 ft. MOST RELIABLE installation contractor, BRH Garver of Houston chose Hobas pipes because their dimensional consistency and wall resiliency have proven to result in the lowest jacking loads and the highest reliability. Garver s confidence was rewarded during the installation. The job was completed in 6 separate drives with the longest being 625 feet. The operating push loads through the clay and shale soils rarely exceeded 30 tons with a maximum peak load of 45 tons! Daily production averaged 106 feet working 10 hours with a single best day of 16 joints (160 feet). Best of all, no pipes were damaged or broken during installation or handling! (continued on page 7) Neat compact job site pleased the community residents. 6

7 MICROTUNNELED SAVES MILLIONS $ (continued from page 6) SATISFIED CUSTOMER Not only was this Derby s first microtunnel experience, it was the first significant microtunnel installation in Kansas. The job was successful in every way as it pleased residents by saving trees, preserving wildlife and minimizing disruption, as well as saving taxpayers $2.4 million in construction costs. Additionally, because the line tested leak-free under 20 to 30 feet of head, structural undermining is prevented and flow capacity is preserved by eliminating infiltration. And perhaps most important, the corrosion resistant Hobas CCFRPM pipes will still be like new well beyond the project design life. Smooth, constant OD Hobas pipes have the lowest jacking loads. MICROTUNNELED FORCE MAIN (continued from page 1) HOBAS ONLY SPEC Since Orlando Standards require all force mains to be rated for 100 psi, the prime design consideration for project consultant, Sverdrup Civil of Orlando, was a reliable pressure pipe suitable for a jacking installation. Additionally, depending on the Bennett Rd. Pump Station volume, the new pipe operates, alternately, as both a force main and a gravity flow line. This demanded an on grade installation (another reason for microtunneling) and a corrosion resistant pipe due to likely generation of sulfides. Further, because the force main was built for flow relief and to handle some redirected flows, good hydraulic characteristics were also important. Because of these requirements only Hobas CCFRPM pipes or equal were allowed by the specifications. INSTALLATION PERFECTION After further consideration of possible alternative materials, Hobas pipes were purchased by contractors, Peters (general) of Owensboro, Kentucky and Kerr (microtunnel sub) of Palmetto, Florida. The microtunneling was accomplished in eight drives ranging from 270 feet to 1000 feet long. Despite the predominately sandy soil, jacking loads were consistently low. Peak start-up loads did not exceed 120 tons and operating loads, even at the conclusion of the All pipes and joints were leak-free at 100 psi after jacking installation. longest drive, were less than 60 tons! This performance allowed all drives to be completed without the use of any intermediate jacking stations. The jacking operation was so smooth, that daily production of 140 feet was frequently achieved with a maximum of 180 feet completed in 9 hours. Perhaps most significant was no pipes were damaged or broken during installation or handling. LEAK-FREE PERFORMANCE The specs required leak-free performance during a 100 psi pressure test for 2 hours on the installed piping. Kerr tested each finished drive section separately shortly after jacking was complete. Except for one of the stainless steel 2" grout bushings (which were factory installed in half of the pipes), each segment passed the pressure test on the first attempt! The cracked lamination of the single leaking bushing was permanently restored in place by a Hobas field representative prior to the successful retest of that segment. Subsequently, the jacked pipes twice more passed the pressure test when Peters made tie-ins to the PVC portions. The nearly flawless performance pleased the City, the designer and the installers. With this success behind us, a second installation of Hobas pressure jacking pipe, 42" diameter, will begin during the 4th quarter on a project in New Jersey. 7

8 Hobas Pipe USA, Inc Richey Road Houston, Texas (281) BULK RATE U.S POSTAGE PAID PERMIT #1339 HOUSTON TX VISIT OUR BOOTH AT THE FOLLOWING UPCOMING TRADE SHOW EXHIBITS: DECEMBER 9-11,1998 Power Generation International Orange County Convention Center Orlando, FL Booth: #1269 JANUARY 12-14,1999 Underground Construction Technology George R. Brown Convention Center Houston, TX Booth: #814 FEBRUARY 11-13, 1999 NUCA 99 Long Beach Convention Center Long Beach, CA Booth: #211 MARCH 1-3, 1999 TAPPI 99 Georgia World Congress Center Atlanta, GA APRIL 6-9, SAME George R. Brown Convention Center Houston, EX APRIL 26-29, 1999 NACExpo 99 Henry B. Gonzalez Convention Center San Antonio, TX Remember, you can visit us anytime at: