NEW ENGLAND COUNCIL ON FOREST ENGINEERING CASE STUDY MARCH 6, 2012

Transcription

1 NEW ENGLAND COUNCIL ON FOREST ENGINEERING CASE STUDY MARCH 6, 2012

2 CONSTRUCTING A TEMPORARY ACCESS ROAD ACROSS AN ATLANTIC WHITE CEDAR ORGANIC BOG FOR THE PURPOSE OF MINING GRAVEL

3 TEMPORARY BOG CROSSING THE FOLLOWING SLIDES ARE OF A PROPOSED ACCESS ROAD THAT WILL CROSS SEVERAL WETLANDS TO ACCESS A GRAVEL DEPOSIT ONE OF THE WETLANDS HAS AN EXEMPLARY PLANT COMMUNITY THAT IS RARE IN MAINE AS DESIGNATED BY MNAP

4 TEMPORARY BOG CROSSING THE PROJECT HAS RECEIVED A PERMIT FROM THE DEP AND ACOE BUT AT LAST CHECK IS WAITING FOR LOCAL PERMITS AND/OR THE ECONOMY THE APPLICANT WAS HOPING TO BEGIN CONSTRUCTION OF THE ACCESS ROAD THIS WINTER OR SPRING BUT WORK HAS NOT YET STARTED

5 TEMPORARY BOG CROSSING ONE OF THE WETLANDS THAT THE ACCESS ROAD WILL CROSS IS AN ORGANIC BOG THE CROSSING IS REQUIRED TO MINIMIZE DISTURBANCE TO THE WETLAND AND ITS HYDROLOGY THE ACCESS ROAD IS PROPOSED TO BE REMOVED AFTER THE GRAVEL IS EXCAVATED

6 TEMPORARY BOG CROSSING THE APPLICANT AND THE REGULATORS SHARE ONE IMPORTANT GOAL: NEITHER WANT THE ROAD TO SINK TO ANY APPRECIABLE DEGREE

7 TEMPORARY BOG CROSSING THE SITE CONTAINS A NUMBER OF RIDGES OF GRAVEL WITH LOW WETLAND AREAS IN BETWEEN THE GRAVEL RIDGES GROUNDWATER INFILTRATES THE GRAVEL RIDGES AND SEEPS OUT AT THE INTERFACE OF A DENSER MINERAL SOIL AND THE GRAVEL ABOVE

8 SITE MAP OF ACCESS ROAD AND GRAVEL DEPOSIT

9 TOPO MAP OF THE SITE

10 FIRST WETLAND CROSSING SITE

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13 SECOND WETLAND CROSSING SITE ORGANIC BOG

14 NOTE LIVE SPHAGNUM MOSS ON THE GROUND SURFACE

15 RUBBER TIRE OBLIGATE WETLAND SPECIES

16 LONGEST/MOST SIGNIFICANT WETLAND CROSSING THE LONGEST WETLAND CROSSING SITE IS THE MOST COMPLEX; IT CONTAINS THREE DIFFERENT CONDITIONS: 1. FIRM PEAT COVERED WITH RED MAPLE LEAVES 2. COVERED WITH LIVE SPHAGNUM MOSS WITH OPEN WATER POCKETS 3. LIVE SPHAGNUM WITH OPEN WATER POCKETS AND FLOWING WATER

17 FIRM PEAT COVERED WITH RED MAPLE LEAVES

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20 LIVE SPHAGNUM WITH OPEN WATER POCKETS

21 TRANSITION FROM RED MAPLE LEAF TO LIVE SPHAGNUM TYPE

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23 NOTE OPEN WATER POCKETS

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25 SHOVEL PIT EXCAVATED INTO PEAT IMMEDIATELY BENEATH THE LIVE SPHAGNUM MOSS WAS A PEAT LAYER THAT WAS FRIABLE AND SATURATED TO THE SURFACE IMMEDIATELY BELOW THE SATURATED PEAT LAYER WAS A MUCH FIRMER PEAT THAT WAS MOIST BUT NOT AS SATURATED AS THE TOP LAYER

26 PEAT PROFILE THE TOP PEAT LAYER THAT WAS SATURATED HAD GRANULAR STRUCTURE AND MANY PLANT ROOTS THE LOWER LAYER OF PEAT HAD MASSIVE OR PLATY STRUCTURE AND NO ROOTS

27 HYDROLOGY OBSERVATIONS IT APPEARD TO ME AS THOUGH WATER WAS PONDING ON THE FIRMER AND MASSIVE PEAT LAYER AND ANY MOVEMENT OF SIGNIFICANCE WAS OCCURRING IN THE TOP PEAT LAYER NO WATER MOVEMENT WAS OBSERVED IN THE OPEN WATER POCKETS OR THE SHOVEL PIT

28 COMPARISON OF PEAT LAYERS SATURATION

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30 SATURATED UPPER PEAT LAYER

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32 MORE DENSE AND LESS SATURATED LOWER PEAT

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34 LIVE SPHAGNUM WITH MOVING WATER

35 NOTE PICTURE PLANTS IN WATER

36 NOTE INTERCONNECTEDNESS OF OPEN WATER POCKETS

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38 WATER MOVEMENT

39 WATER MOVEMENT

40 GRAVEL RIDGE AT WETLAND/UPLAND BOUNDARY

41 STANDARDS FOR ROADS ON ORGANIC SOILS MOST OF US HAVE VERY LITTLE EXPERIENCE WITH THE CONSTRUCTION OF ROADS OVER ORGANIC SOILS PARTICULARLY WHEN THE ROADS CAN NOT CONNECT WITH THE MINERAL SOIL BELOW AND HAVE TO BE REMOVED AFTER A FEW YEARS

42 ORGANIC SOIL UNDER ROAD TO WEST QUODDY HEAD

43 SELECTION OF CRITERIA FOR ACCESS ROAD BOG CROSSING THE CONSULTANT SEARCHED FOR INFORMATION ON HOW BEST TO CONSTRUCT SUCH AN ACCESS ROAD BUT DID NOT FIND MUCH USEFUL INFORMATION I WAS CONSULTED AND THIOUGH I HAD NO HARD DATA PROVIDED A RECOMMENDATION BASED ON KNOWLEDGE, LOGIC AND REASONING

44 ACCESS ROAD BOG CROSSING CONSTRUCTION DETAILS CUT TREES BUT LEAVE STUMPS AND ROOTS IN PLACE FOR STRUCTURAL SUPPORT IN A 36 FOOT WIDE PATH LAY SLASH DOWN BETWEEN STUMPS FOR ADDED SUPPORT-USE SLASH FROM ADJACENT UPLANDS IF NECESSARY LEVEL ROAD AND SHOULDER FOOTPRINT, TO THE TOP OF STUMPS, WITH STUMP GRINDINGS OR WOOD CHIPS - ESSENTIALLY MAKING A MATTRESS

45 ACCESS ROAD BOG CROSSING CONSTRUCTION DETAILS LAY FILTER FABRIC ON LEVELED ROAD AND SHOULDER FOOTPRINT LAY A LAYER OF 36 FOOT LONG LOGS DOWN ON FILTER FABRIC ALTERNATING BUTT AND TOPS SO THAT THE THICKNESS AND SUPPORT IS SIMILAR OVER THE ENTIRE LAYER PERPENDICULAR TO THE DIRECTION OF THE ROAD CABLE LOGS TOGETHER TO FORM A MATT OR MATTS LAY ANOTHER LAYER OF LOGS DOWN ON THE TOP OF THE FIRST LAYER OF LOGS IN A SIMILAR MANNER TO THE FIRST LAYER BUT THEY DO NOT NEED TO BE CABLED TOGETHER

46 ACCESS ROAD BOG CROSSING CONSTRUCTION DETAILS THE TWO LAYERS OF LOGS WILL PROVIDE ADDED STRENGTH TO SUPPORT THE GRAVEL ROAD SURFACE AND LOADED DUMP TRUCKS AND THE VOIDS BETWEEN THE LOGS WILL ALLOW WATER MOVEMENT THROUGH THE ROAD BASE SIMILAR TO A ROCK SANDWICH

47 ACCESS ROAD BOG CROSSING CONSTRUCTION DETAILS 36 FOOT LONG LOGS WERE CHOSEN TO PROVIDE REASONABLE SUPPORT (NO FORMULA WAS USED TO MAKE THAT DETERMINATION) AND TO GIVE 5 FEET OF CLEARANCE ALONG EACH SIDE OF THE ROAD FOR SNOW PLOWING ACCUMULATION-CABLING THE BOTTOM LAYER OF LOGS TOGETHER AS A MATT WILL PROVIDE ADDED STRENGTH

48 ACCESS ROAD BOG CROSSING CONSTRUCTION DETAILS IN THE AREA OF THE LONGEST BOG CROSSING WHERE MOVING WATER WAS OBSERVED SOME OF THE TOP LAYER OF LOGS WILL BE REPLACED BY METAL PIPES OF A SIMILAR DIAMETER TO THE LOGS TO ACT AS SMALL CULVERTS THAT WILL SPREAD OUT THE WATER OVER THE ENTIRE AREA WHERE MOVING WATER WAS OBSERVED

49 ACCESS ROAD BOG CROSSING CONSTRUCTION DETAILS THE DEP AND ACOE WANTED TO INSTALL A CULVERT(S) TO MAINTAIN THE NATURAL HYDROLOGY BUT I FIGURED THEY WOULD JUST BECOME EMBEDDED IN THE PEAT AND NOT FUNCTION AS PLANNED THIS WAS REINFORCED AFTER STUDYING HOW THE HYDROLOGY WORKED IN THE BOG

50 ACCESS ROAD BOG CROSSING CONSTRUCTION DETAILS PLACE A FILTER FABRIC ON TOP OF THE SECOND LAYER OF LOGS ADD A FOOT OF GRAVEL 24 FEET WIDE ON TOP OF THE SECOND LAYER OF FILTER FABRIC (28 WIDE AT BASE) USE STUMP GRINDINGS FOR 4 FOOT SHOULDERS ON EACH SIDE OF THE ROAD TOO PREVENT GRAVEL FROM BEING PUSHED INTO THE ORGANIC BOG-STUMP GRINDINGS WILL BE SIMILAR TO THE WOODY MATERIAL ALREADY PART OF THE NATURAL BOG

51 BOG CROSSING ACCESS ROAD CROSS-SECTION

52 PERIODIC INSPECTIONS THE DEP AND ACOE ARE CONCERNED ABOUT THE POSSIBILITY OF SIGNIFICANT SUBSIDENCE OF THE ROAD AND RESULTING ALTERATION OF THE NATURAL HYDROLOGY THEY WILL BE REQUIRING THE APPLICANT TO PERIODICALLY CHECK THE ELEVATION OF THE ROAD

53 PERIODIC INSPECTIONS SHOULD THE ROAD SUBSIDE TO A SIGNIFICANT DEGREE THE BOG CROSSING SECTION OF THE ROAD MAY BE LIMITED TO ONE VEHICLE AT A TIME AND/OR LOAD LIMITS MAY BE APPLIED

54 DOCUMENTATION I INTEND TO PRIODICALLY VISIT THE SITE, AS DO A NUMBER OF OTHERS, AND WILL TAKE LOTS OF PHOTOS THEY MIGHT MAKE AN INTERESTING PRESENTATION AT A FUTURE NERCOFE MEETING

55 QUESTIONS

56 ROCK SANDWICHES AKA PERMEABLE ROAD BASE

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58 WHAT IS A ROCK SANDWICH? IT IS A LAYER OF STONE OR CRUSHED ROCK SANDWICHED BETWEEN 2 LAYERS OF FILTER FABRIC USED AS A ROAD BASE THOUGH THE DEP-BMP CALLS FOR A MINIMUM 12 THICK LAYER OF 3-6 STONE, ACTUAL SANDWICH THICKNESS AND STONE DIAMETER CAN BE ADJUSTED ACCORDING TO SITE SPECIFIC CONDITIONS AND AVAILABILITY OF STONE

59 WHAT IS ITS PURPOSE *MAINTAINS NATURAL HYDROLOGY *STRENGTHENS ROAD BASE *PREVENTS FROST ACTION IN ROAD *REQUIRES LITTLE MAINTENANCE *LASTS INDEFINATELY *PREVENTS SCOURING ASSOCIATED WITH CONCENTRATED FLOW

60 PURPOSE *THEY DO NOT HEAVE *THEY DO NOT RUST *THEY DO NOT COLLAPSE *THEY DO NOT FREEZE DUE TO LATENT HEAT OF GROUNDWATER *ONLY REQUIRE SHALLOW DITCHES WHICH NEED MINIMAL MAINTENANCE *PUTS COLD CLEAN GROUNDWATER BACK INTO THE GROUND

61 WHERE SHOULD ROCK SANDWICHES BE USED ROCK SANDWICHES CAN BE USED ALMOST ANYWHERE BUT ARE DESIGNED TO BE USED PRIMARILLY IN TWO LOCATIONS: WETLAND CROSSINGS & CUTS BELOW THE GROUNDWATER TABLE

62 ROCK SANDWICHES IN WETLAND CROSSINGS ROCK SANDWICHES WORK WELL IN CROSSING MOST WETLANDS EXCEPT FOR WETLANDS THAT ARE ORGANIC BOGS PROVIDES EXCELLENT STRUCTURAL SUPPORT WHEN CROSSING WETLANDS

63 ROCK SANDWICHES IN CUT SLOPE ROADS ROCK SANDWICHES CAN BE USED IN ALMOST ANY CUT BUT ARE MOST EFFECTIVE IN CUTS BELOW THE SEASONAL GROUNDWATER TABLE MOST EFFECTIVE IN SOILS THAT HAVE HIGH PERMEABILITY AND A SHALLOW RESTRICTIVE LAYER OR ARE SHALLOW TO BEDROCK

64 ROCK SANDWICHES IN CUT SLOPE ROADS THE MOST BENEFICIAL SITES FOR ROCK SANDWICHES IN CUT SLOPE ROADS ARE: *STEEP SLOPES (THE STEEPER THE MORE BENEFICIAL) *SIGNIFICANT UPSLOPE WATERSHED (THE LARGER THE MORE BENEFICIAL)

65 ROCK SANDWICHES IN CUT SLOPE ROADS *RECONNECTING GROUNDWATER SEEPS *RECONNECTING ROCK FILLED CHANNELS (USE STONE SIZE SIMILAR TO THE NATURAL STONE IN THE ROCK FILLED CHANNEL) *RECONNECTING COARSE TEXTURED SUBSOIL LAYERS WHERE PIPING IS PRESENT

66 WHERE ROCK SANDWICH USE IS QUESTIONABLE ROCK SANDWICHES DO NOT PROVIDE THE SAME VALUE FOR ROAD CUTS IN SLOWLY PERMEABLE SOILS SUCH AS LACUSTRINE SEDIMENTS OR MARINE SEDIMENTS AS THEY DO IN MORE PERMEABLE SOILS SUCH AS SANDLY LOAM TO LOAMY SAND GLACIAL TILLS

67 ROCK SANDWICH ON LEVEL GROUND

68 ROCK SANDWICH ON SLOPING GROUND WITH CUT

69 M & H Construction 3039 Main Street Route 4 North ~ P.O. Box 565 Rangeley, ME September 23, 2011 Mr. David Rocque Department of Agriculture State of Maine Dear Dave, RE: Costing information for blanket 1. I am very sorry we have no pictures of rock blankets actually being installed. I sent you some pictures but they should be at high water. If any of the pictures you could use further information please call me or x100. I will give you some general guidelines on cost of the rock blankets. For each 100 SF of the blanket at a depth of 18 rock and 6 of Type D gravel and 6 of surface gravel. Excavator 2 HR $110 HR Dump trucks 2 $65 Non-woven fabric 22 $2.00 SY Rock 6 to 12 6 $15.00 CY Del Gravel Type D 2 $10.50 CY Del ½ crushed gravel 2 $16.00 Del Sincerely, 1. Excavate and have dump truck haul of to get a base for rock blanket. 2. Place a layer of non-woven fabric, then place rip rap, then another layer of fabric, then type D gravel and then surface course of crushed. These do work very well keeping surface water from channeling but they work extremely well intercepting sub surface water and it is a big help keeping a building site dry. Kenneth J. Haley General Manager

70 ROCK SANDWICH INSTALLATION

71 ROCK SANDWICH INSTALLATION IN CUT

72 ROCK SANDWICH WETLAND CROSSING

73 ROCK SANDWICH WETLAND CROSSING

74 ROCK SANDWICH WETLAND CROSSING

75 ROCK SANDWICH WETLAND CROSSING

76 ROCK SANDWICH WETLAND CROSSING IN WINTER

77 NOTE UNSTABILIZED MINERAL SOIL UPSLOPE OF ROCKS

78 DOWNSLOPE OF ROCK SANDWICH

79 ROAD ROCK SANDWICH AT WETLAND AND STREAM

80 SEASONAL STREAM ABOVE ROCK SANDWICH

81 ROCK SANDWICH UPSLOPE SIDE OF ROAD

82 ROCK SANDWICH DOWN SLOPE SIDE OF ROAD

83 SUBDIVISION ROAD WITH ROCK SANDWICH AT CUT

84 UPSLOPE SIDE OF ROAD WITH CUT AND ROCK SANDWICH

85 OVERFLOW CULVERT AT CUT AND ROCK SANDWICH

86 OVERFLOW CULVERT AT ROCK SANDWICH AND CUT

87 DOWNSLOPE SIDE OF ROAD ST CUT AND ROCK SANDWICH

88 DOWNSLOPE SIDE OF ROAD AT CUT AND ROCK SANDWICH

89 DOWNSLOPE SIDE OF ROCK SANDWICH NOTE WATER

90 UPSLOPE SIDE OF ROCK SANDWICH

91 UPSLOPE SIDE OF ROCK SANDWICH

92 DOWNSLOPE SIDE OF ROCK SANDWICH

93 ELLIOTSVILLE TWP ROAD ROCK SANDWICH UPSLOPE

94 ELLIOTSVILLE TWP ROCK SANDWICH DOWNSLOPE

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96 DAVID P. ROCQUE STATE SOIL SCIENTIST MAINE DEPARTMENT OF AGRICULTURE STATE HOUSE STATION #28 AUGUSTA, MAINE PHONE: (207)