Drop Structure Design for Wastewater and Stormwater ...

1 1/9/04 3:47 PM Page 1. 1998 William Barclay Parsons Fellowship Parsons Brinckerhoff Monograph 14. drop Structure Design for Wastewater and Stormwater Collection Systems Scott Williamson, Lead Engineer Parsons Brinckerhoff Quade & Douglas, Inc. August 2001. 1/9/04 3:47 PM Page 2. *MVWX TVMRXMRK . 'ST]VMKLX 4 EVWSRW &VMRGOIVLSJJ -RG . %PP VMKLXW VIWIVZIH 2S TEVX SJ XLMW [SVO QE] FI VITVSHYGIH SV YWIH MR ER] JSVQ SV F]. ER] QIERW KVETLMG IPIGXVSRMG SV QIGLERMGEP MRGPYHMRK TLSXSGST]MRK VIGSVHMRK . XETMRK SV MRJSVQEXMSR WXSVEKI SV VIXVMIZEP W]WXIQW [MXLSYX TIVQMWWMSR SJ XLI TYFPMWLIV . 4 YFPMWLIH F]. 4 EVWSRW &VMRGOIVLSJJ. 3RI 4 IRR 4PE^E. 2I[ =SVO 2I[ =SVO . +VETLMGW (EXEFEWI + . 1/9/04 4:13 PM Page i CONTENTS. FOREWORD. INTRODUCTION . 4 YVTSWI SJ XLMW 1 SRSKVETL . 1 SRSKVETL 3 VKERM^EXMSR . drop Structure BASIC FUNCTIONS AND TYPES.)

2 &EWMG *YRGXMSRW . +IRIVEP (VST 7 XVYGXYVI 8]TIW ERH 'SQTSRIRXW . 3 XLIV 8]TIW SJ (VST 7 XVYGXYVIW . 'SQTEVMWSR SJ (VST 7 XVYGXYVI 8]TIW . PLANNING AND Design CONSIDERATIONS . *PS[ :EVMEFMPMX] ERH 'SPPIGXMSR 7]WXIQ 8]TI . )RIVK] (MWWMTEXMSR . (VST 7 XVYGXYVI 0 SGEXMSR . %MV )RXVEMRQIRX ERH :IRXMPEXMSR . 3 HSV ERH 'SVVSWMSR 'SRXVSP . 7 YFWYVJEGI 'SRHMXMSRW ERH 'SRWXVYGXMSR . 3 TIVEXMSRW ERH 1 EMRXIRERGI . Design METHODOLOGY . 6 SPI SJ ,]HVEYPMG 1 SHIPMRK MR (VST 7 XVYGXYVI (IWMKR . :SVXI\ (VST 7 XVYGXYVIW . 4 PYRKI (VST 7 XVYGXYVIW . drop Structure APPURTENANCES . %GGIWW 7 LEJXW . 7]WXIQ 1 SRMXSVMRK ERH 'SRXVSPW . (IFVMW 7 GVIIRMRK . APPENDIX A: REVIEW OF drop Structure /TUNNEL SYSTEMS . APPENDIX B: SUMMARY OF drop STRUCTURES BY GEOGRAPHICAL. LOCATION AND INLET TYPE . REFERENCES . M. 1/9/04 4:13 PM Page ii MM.))))))))

3 1/9/04 4:13 PM Page iii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

5 % 7 GLIQEXMG SJ (VST 7 XVYGXYVI [MXL :SVXI\ -RPIX 4 MXXWFYVKL 4% . % 4 PYRKI *PS[ (VST 7 XVYGXYVI JSV XLI 9 VFER 'SQQYRMX] 1 SRXVIEP 'EREHE . % % 8]TMGEP (VST 7 XVYGXYVI JSV XLI 'MX] SJ 7X 4 EYP 1 MRRIWSXE . % 7 GLIQEXMG SJ ;IPPLSPI 1 SVKER 6YR 7I[IV 'PIZIPERH 3 LMS . % 7 GLIQEXMG SJ ;IPPLSPI 4 IXVMI 7 XVIIX 7I[IV 'PIZIPERH 3 LMS . % 7 GLIQEXMG SJ ;IPPLSPI 1 MRRIETSPMW 1 MRRIWSXE . % -WSQIXVMG SJ (IIT (VST 7 XVYGXYVI 6 SGLIWXIV 2I[ =SVO . MMM. 1/9/04 4:13 PM Page iv LIST OF TABLES. CHAPTER 2. (VST 7 XVYGXYVI )ZEPYEXMSR &EWIH SR -RPIX 8]TI . CHAPTER 3. 8]TMGEP 'SRGIRXVEXMSRW SJ 'SQTSRIRXW MR 9 RXVIEXIH ;EWXI[EXIV . 3 HSVSYW 'SQTSYRHW MR 9 RXVIEXIH ;EWXI[EXIV ERH (IXIGXEFPI 0 MQMXW . 'SWXW JSV 3 HSV 'SRXVSP . )\EQTPI 1 EXVM\ )ZEPYEXMSR SJ +EW 4 LEWI 3 HSV 'SRXVSP 8 VIEXQIRX . )JJIGX SJ 7I[IV 'SRHMXMSRW SR ,]HVSKIR 7 YPJMHI 'SVVSWMSR.)))]]

6 8]TMGEP ;EWXI[EXIV 'LEVEGXIVMWXMGW XLEX 4 VSQSXI ,]HVSKIR 7 YPJMHI. +IRIVEXMSR . 1 IXLSHW XS 'SRXVSP ,]HVSKIR 7 YPJMHI 'SVVSWMSR . 0 MRMRK 1 EXIVMEPW . 4 PEWXMG 1 IQFVERIW 9 WIH JSV 'SVVSWMSR 4 VSXIGXMSR . 'SQTEVMWSR SJ 0 MRMRKW ERH 1 IQFVERIW . 'SVVSWMSR 6 IWMWXERX 4 MTI 1 EXIVMEPW . CHAPTER 4. 1 YPXMTPMIVW 9 WIH XS (IXIVQMRI -RMXMEP (MQIRWMSRW SJ (VST 7 XVYGXYVIW . ,IPMGEP (MQIRWMSRW JSV (IWMKR *PS[W JVSQ XS '*7 . MZ. 1/9/04 3:50 PM Page 1. INTRODUCTION.. 1/9/04 3:50 PM Page 2.. 1/9/04 3:50 PM Page 3. INTRODUCTION. PURPOSE OF THIS MONOGRAPH. 8LI TYVTSWI SJ XLMW QSRSKVETL MW XS JSWXIV ER YRHIVWXERHMRK SJ MWWYIW VIPEXIH XS HVST. WXVYGXYVIW ERH XYRRIP W]WXIQW MR SVHIV XS EWWMWX MR KYMHMRK XLI HIWMKR TVSGIWW JVSQ XLI GSR . GITXYEP WXEKI XLVSYKL GSRWXVYGXMSR ERH STIVEXMSR 8LI GSPPIGXMSR W]WXIQW YTWXVIEQ ERH.)))))

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

10 RIRXW EW [IPP EW RSQIRGPEXYVI YWIH MR WYFWIUYIRX GLETXIVW % WLSVX LMWXSVMGEP TIVWTIG . XMZI SR XLI HIZIPSTQIRX SJ HVST WXVYGXYVI HIWMKR MW MRGPYHIH . 'LETXIV VIZMI[W XLI TPERRMRK ERH HIWMKR GSRWMHIVEXMSRW XLEX QE] FI YWIH XS KYMHI XLI. HIWMKR TVSGIWW (MWGYWWMSR SR GSPPIGXMSR W]WXIQ X]TI JPS[ ZEVMEFMPMX] ZIRXMPEXMSR SHSV.. 1/9/04 3:50 PM Page 4. GSRXVSP GSVVSWMSR TVSXIGXMSR ERH SXLIV MWWYIW EVI TVSZMHIH XS EWWMWX MR XLI HIZIPSTQIRX SJ. TVSNIGX HIWMKR GVMXIVME . 'LETXIV VIZMI[W HVST WXVYGXYVI HIWMKRW ERH L]HVEYPMG TIVJSVQERGI EWWSGMEXIH [MXL XLI. ZEVMSYW HVST WXVYGXYVI HIWMKRW GYVVIRXP] MR YWI (IWMKR MWWYIW EWWSGMEXIH [MXL WTIGMJMG. HVST WXVYGXYVI X]TIW EVI HMWGYWWIH ERH XLI VSPI SJ L]HVEYPMG QSHIPW ERH WTIGMEP GSRWMH . IVEXMSRW MR IZEPYEXMRK HVST WXVYGXYVI L]HVEYPMGW MW VIZMI[IH (IWMKR QIXLSHSPSK] YWIH XS.)))