CULVERT MAINTENANCE. A compilation by Ir Zulkhairi Hasan, Ramlah Abdul Rahman, and Satyaanandha Rao Sanasi

Transcription

1 CULVERT MAINTENANCE A cmpilatin by Ir Zulkhairi Hasan, Ramlah Abdul Rahman, and Satyaanandha Ra Sanasi General A culvert is a cutting under r beside a rad which allws water t drain, rather than becming stagnant and making rad cnditins hazardus. Technically, nly an enclsed tunnel under a rad can be classified as a culvert, and a cutting next t a rad is called a ditch, but sme English speakers use the term culvert t refer t either. Culverts are a vital part f the system used t drain rads and drives, keeping them safe and extending their lifetimes. Ideally, a culvert is installed when a rad is built, either by the lcal highway authrity r a prperty wner, if the culvert is n private land. Generally, if a sectin f a rad lies in a depressed area f grund r a regin subject t flding, a culvert shuld be installed t facilitate drainage. The culvert is laid int the rad bed while it is being built, and is kept clear by maintenance crews during rutine checks f the radway thrughut the year. Culverts serve tw majr functins: 1. A culvert allws water t drain under the rad, rather than stagnant r pling n tp f it, making the surface safer fr drivers. Stagnant water n a rad can cause cars t experience hydrplane, cnceal hazards n the radway, and will ultimately deterirate the radway, causing it t break dwn quickly. 2. T keep water frm cllecting alng the verges f the radway and cause scuring r water pnding that may cause hazard t users. This will extend the life f the rad and prevents the edges f the radway frm slwly crumbling away, psing a safety hazard t drivers. A culvert can be built frm a wide variety f materials, depending n the size and where it is installed. Cncrete, metal, and plyethylene are all cmmn chices t line the cutting used t make a culvert, preventing the sides frm caving in. Extremely large culverts can be big enugh t stand up in, allwing fr a heavy vlume f winter water, while small nes may nt be much larger than husehld plumbing: just big enugh t divert the water flw t a drainage area. If a culvert is nt effective enugh, it may be replaced with a small raised bridge r elevated structure r viaduct t elevate the radway abve the frequently flded area.

2 Culvert Inspectin The key f effective maintenance is regular schedule f inspectins t determine the maintenance need and t ensure that required maintenance is dne. Inspectins are dne in a regular interval during the service life f the culvert t ensure that satisfactry cnditins exist and t evaluate needs fr cleanup and repair in advance f the wet seasn. Inspectins are als made t mnitr existing defects that have nt been repaired as well as t mnitr any defects that had been repaired. Inspectins can be divided int the fllwing categries: General Inspectins Is a rutine and frequent inspectin cnducted t culverts lcated in critical areas, i.e. flding areas and areas adjacent t third party develpment. The inspectins are undertaken at regular/frequent interval, as and when required t detect fr damage structure and blckage f waterway at early stage within a visible range. Peridic Inspectin Is a primarily designed t carry ut mre detail inspectin peridically fr culverts n ft by accessing the subject as clse as pssible. These inspectins shuld determine the current serviceability and structural status f the culverts. The frequencies f inspectins are undertaken at interval f nce a year. Special Inspectin Is the supplementary inspectin in additin t the general inspectin and peridic inspectin, fr example, in ccasinal cases such as strm and heavy rain. Elements fr Inspectin Check the accumulatin f debris, siltatin r ther flw impediments at inlets and utlets Inspect the culvert barrel, if pssible, fr tree r ther vegetatin rts, mineral depsits, trash r silt accumulatins and ther freign bjects bstructing flw paths. Examine inlet and utlet areas fr evidence f sil ersin, which generally leads t scur, undermining and caving f adjacent sil supprting the culvert. Sil ersin quickly leads t reduced structural and hydraulic perfrmance. Inspect all visible structures such as sumps, headwalls, wingwalls, culverts and aprns fr sign f wear r breakage. Check upstream fr evidence f backup r prlnged surface water presence that indicated reduced inflw. Check dwnstream fr evidence f freign material that indicate reduce filtratin f sil r structural degradatin f drainage system itself.

3 Inspectin f waterway Hydraulic Capacity - t determine any high water marks indicating fld r presence f bstructin causing pnding Siltatin and Debris in r near Culvert - t check the severity f siltatin and debris within the culvert barrel as well as at inlet and utlet f culvert and it depth shall nt be greater than 0.2D where D is diameter f pipe culvert r height f bx culvert. Vegetatin - t check the vegetatin grwth within the waterway bth at inlet r utlet f the culvert and cverage shall nt be greater then 20% f waterway sectin. Scuring r Undermining - t check fr scuring and undermining at the ends f culvert r at the edge f aprn. Inspectin f Culvert Structures a. Reinfrced Cncrete Pipe / Bx Culvert / VBC - t check the culvert barrel fr settlement, abrasin f lining cracking / spalling f cncrete, and crrsin f reinfrcement. b. Crrugated Metal Pipe Culvert (CMP) / High Density Ply Ethylene (HDPE) -t check fr change f shape f culvert barrel, abrasin f lining, damaged r deteriratin t paint r galvanizing, crrsin f metal and lse r crrded blts. c. Inlet and utlet structure fr Drainage / RHS and LHS Entrance fr VBC -t check mvement (settlement r sideway mvement) -fr cncrete structures t check fr cracking / spalling f cncrete and crrsin f reinfrcement. -fr masnry structures t check fr cracking, pr pinting r deteriratin f bricks r stne.

4 Rutine Maintenance Wrks r Schedule Repair Wrk Optins fr Culvert Maintenance Strategy Objective Wrk Optin Rutine Maintenance Keep a culvert in a unifrm -debris and sediment remval and safe cnditin by repairing -thawing frzen culverts specific defects as they ccur Rehabilitatin Takes advantage f the -jint sealing remaining usable culvert -mrtar repair structure t recnditin a -invert paving culvert -scur preventing -lengthening f culvert Upgrade t Equal Replacement Upgrade t prvide service -Additin, repair, r replacement r appurtenant that is equal t that prvided structures by a new structure -Lining f the barrel -Prvisin f safety grates r safety barriers -Lengthening f the culvert Replacement Prvide a cmpletely new Can be accmpanied by: culvert with a new service life -Realignment -Hydraulic structure and safety imprvements -Change in culvert shape r material This table illustrates wrk ptins fr different strategies, such as rutine maintenance, preventative maintenance, rehabilitatin, and replacement. Fr each strategy the bjectives are different and at least tw wrk ptins are listed.

5 Cnclusins It is vital t ensure the functinality f the culverts is at its ptimum cnditin. Schedule rutine maintenance and peridic up-keeping f the cnditin f the culverts and their surrunding must be prgrammed and mnitred at all times. Any discrepancy in the prgramme will affect the perfrmance f the culvert and as a result mre allcatins have t be spent in ensuring that the culverts are in gd wrking cnditin. The authrity wh is maintaining the rad r prperty must have a prper schedule and persnnel t cnduct the inspectin activity. A culvert inventry and thus database must be available as well as the drawings fr cntinuity f the maintenance. A culture f maintenance must be instilled t ensure the culvert life is prlnged and secured.

6 References: i) Ttal Expressways maintenance management Systems (Teman), Inspectin Manual, Prjek Lebuhraya Utara Selatan, ii) Assessment and Rehabilitatin f Existing Culverts, A Synthesis f Highway Practice, Transprtatin Research Bard, NCHRP Synthesis 303, 2002 iii) Busy Beaver Culvert Cleaning-- Prfessinal, Affrdable Culvert Maintenance,1996 iv) Vermnt Agency Of Transprtatin-Culvert & Ditch Maintenance Prcedures, March 27, 2002 v) Rad Management Jurnal, by TranSafety, Incrprated, 1997 vi) Rad Maintenance in Big Surf ; Handbk fr Frest and Ranch Rads, The Green Bk",1994