Gas Station Structural Engineering in Highland: Complete 2025 Design Guide

**Occupancy Classification**:

• **Fuel canopy area**: Group H-2 (High Hazard - Moderate Hazard) per CBC Section 307.4 for flammable fuel dispensing, or Group U (Utility/Miscellaneous) if canopy is open-air without enclosed spaces
• **Convenience store**: Group M (Mercantile) per CBC Section 309
• **Car wash or service area**: Group F-2 (Factory/Industrial - Low Hazard) per CBC Section 306.3
• **Food service area**: Group A-2 (Assembly) for restaurant seating per CBC Section 303

**Live Load Requirements** (CBC Table 1607.1):

• **Canopy structure**: 20 psf minimum live load (snow/maintenance access)
• **Convenience store floors**: 40-60 psf (retail/business occupancy)
• **Storage rooms**: 125 psf
• **Sidewalks and plaza areas**: 60 psf uniform, 200 lbs concentrated

**Vehicle Live Loads** (ASCE 7-22 Section 4.10):

• **Passenger vehicle areas**: 40 psf uniform or concentrated wheel loads (3,000 lbs)
• **Truck traffic areas**: Design for HS-20 loading (80,000 lb tanker trucks) or actual tanker truck loads
• **Pavement and fuel dispenser islands**: Both uniform area loads and concentrated axle loads

**Wind Loads**: Highland is subject to significant wind exposure:

• **Design wind speed**: 90-95 mph (3-second gust, Risk Category II per ASCE 7-22)
• **Higher wind pressures on elevated canopies**: Canopy structures typically 14-18 ft tall act as wind sails
• **Uplift resistance critical**: Wind uplift can exceed downward gravity loads—canopy columns must be designed for tension
• **Signage and equipment**: High-profile pylon signs (30-60 ft tall) subject to extreme wind loads

**Seismic Design**: Highland is in **Seismic Design Category D** (high seismic risk). Critical requirements include:

• Canopy structure designed for lateral seismic forces per CBC Chapter 16
• Base connections designed for shear, uplift, and overturning
• Flexible connections for utilities (fuel lines, electrical) to accommodate seismic movement
• Anchorage of convenience store shelving, equipment, and building components
• Pylon sign seismic design per CBC Section 1609.1.1.3

**Plan Review Process**:

• Submit structural plans through City of Highland (in-person or online)
• Gas stations require **licensed California structural engineer's seal** (SE preferred)
• Multiple permits required:
• **Building permit** (canopy, convenience store, structures)
• **Underground storage tank permit** (California State Fire Marshal and local fire)
• **Plumbing, mechanical, electrical permits**
• **Fire Department review**: Fire suppression systems, emergency shutoffs, fire access
• **Public Works review**: Site grading, drainage, utilities, traffic circulation
• **California State Fire Marshal**: UST installation approval

**Permit Timeline**:

• Initial plan check: 4-6 weeks typical (gas stations are complex projects)
• Resubmittal review: 2-3 weeks
• State Fire Marshal review: 2-4 weeks (concurrent)
• Total permit process: 10-16 weeks typical

**Special Requirements for Highland**:

• **Petroleum facilities**: Must comply with California Health & Safety Code Division 20, Chapter 6.7 (Underground Storage Tanks)
• **Fire Marshal approval**: San Bernardino County Fire Department reviews all petroleum facility plans
• **Environmental permits**: San Bernardino County Environmental Health oversight for UST installation, monitoring, and closure
• **Water quality**: Stormwater management plan required, oil/water separators for drainage
• **Traffic access**: Caltrans approval may be required if site has access to state highway

**California State Fire Marshal (CSFM)**:

• All UST installations require **CSFM permit**
• UST system must meet current standards (double-walled tanks, leak detection, spill containment)
• Certified UST installer required
• Inspection and testing before facility can operate

**Underground Storage Tank Requirements**:

• **Tank construction**: Double-walled fiberglass or steel-clad-polyethylene (Xerxes, Containment Solutions, etc.)
• **Capacity**: Typically 10,000-30,000 gallons per tank; multiple tanks for different fuel grades
• **Leak detection**: Interstitial monitoring between tank walls plus secondary containment
• **Overfill protection**: Mandatory overfill prevention devices
• **Corrosion protection**: Cathodic protection for metal components

**US EPA Requirements**:

• Federal UST regulations (40 CFR Part 280)
• Financial responsibility requirements
• Release detection and reporting
• Operator training requirements

**Canopy Sizing and Configuration**:

• **Typical dimensions**:
• Small station: 60-80 ft × 30-40 ft (2-3 dispenser islands)
• Medium station: 100-120 ft × 40-50 ft (4-6 dispenser islands)
• Large station: 120-150+ ft × 50-60 ft (6-8+ dispenser islands)
• **Height**: 14-18 ft clear height minimum (accommodate tall vehicles, RVs, trucks)
• **Column spacing**: 30-50 ft typical (maximize vehicle access and visibility)
• **Cantilevers**: 10-20 ft overhangs beyond columns common

**Live Loads**:

• **Roof live load**: 20 psf minimum (CBC Table 1607.1 for canopies)
• **Maintenance/access**: 100 psf concentrated load
• **Snow load** (Highland): 15-25 psf ground snow load, reduced per ASCE 7-22 (5-15 psf typical on canopy)

**Wind Loads** (Critical for Canopies):

• **Design wind pressure**: 20-35 psf on projected canopy area (varies with height, exposure, building configuration)
• **Uplift**: Wind creates negative pressure on underside of canopy—can exceed gravity loads
• **Net uplift**: Column design typically governed by uplift (tension) rather than compression
• **Overturning**: Large canopies act as "sails"—foundation design must resist overturning moment

**Example - 100 ft × 40 ft Canopy in Highland**:

• Dead load: 30 psf × 4,000 sq ft = 120,000 lbs (60 kips)
• Wind uplift: 25 psf × 4,000 sq ft = 100,000 lbs (50 kips)
• Net uplift: 50 kips - 60 kips = **-10 kips** (still downward, but close)
• With load factors (1.0D - 1.6W): **Columns in tension!** Must design column connections for uplift

**Connection Design**:

• Base plates anchored to concrete foundations with anchor bolts
• **Anchor bolts**: 1" to 1.5" diameter, 18-30" embedment typical
• Design for tension (uplift), shear (lateral wind/seismic)
• Moment-resisting connections if required for lateral system
• Exposed bases require corrosion protection (galvanizing, protective coatings)

**Seismic Design**:

• Canopy structure must meet CBC seismic requirements
• **Lateral system**: Moment frames, braced frames, or cantilever columns
• Open canopies limit bracing options—often use moment connections
• Design for lateral forces in both directions
• Flexible utility connections to accommodate seismic drift

**Corrosion Protection**:

• All steel exposed to weather: hot-dip galvanized or painted with high-performance coatings
• Fuel vapors and vehicle emissions accelerate corrosion
• Anchor bolts and embedded steel: galvanized or stainless steel
• Regular inspection and maintenance critical

**Tank Sizing**:

• **Typical gas station**: 3-5 tanks totaling 40,000-80,000 gallons
• Regular gasoline: 12,000-20,000 gallons
• Plus/Premium gasoline: 10,000-15,000 gallons
• Diesel: 10,000-15,000 gallons
• Reserve capacity: Often 1 or 2 additional tanks
• **Large stations**: 80,000-150,000+ gallons total capacity

**Excavation**:

• Depth: 10-14 ft typical (tank height 8-10 ft + 2-4 ft cover)
• Width/length: Depends on number and orientation of tanks, typically 15-30 ft wide × 30-60 ft long
• **Excavation support**: Shoring or sloped excavation required during construction per OSHA standards
• **Dewatering**: Required if groundwater encountered (rare in Highland due to deep water table)

**Structural Backfill**:

• USTs must be embedded in proper backfill material for support and corrosion protection
• **Backfill material**: Clean sand (max 1/4" to 1/2" size) or pea gravel
• **Compaction**: 90-95% relative density
• **Bedding**: 6-12 inch clean sand layer beneath tanks
• **Cover**: Minimum 12 inches clean sand above tanks before general backfill

**Tank Anchorage**:

• **Flotation prevention**: Tanks are buoyant when empty and groundwater is present
• Highland typically has deep groundwater (>30 ft), so flotation rarely an issue
• If high groundwater possible: Tanks anchored to concrete deadmen or held down with reinforced concrete straps
• **Seismic restraint**: Tanks must resist sliding and overturning during earthquakes
• Tank-to-pipe connections designed for seismic movement (flexible joints)

**Structural Loading Above Tanks**:

• **Soil cover**: Minimum 2-3 ft above tanks to distribution loads
• **Traffic loads**: Design for HS-20 truck loads (80,000 lb tanker trucks driving over tanks)
• **Pavement design**:
• Asphalt: 4-6 inches over 6-8 inches aggregate base (AB)
• Concrete: 6-8 inches reinforced concrete
• **Load distribution**: Traffic loads spread through soil to tank—adequate cover critical

**Tank Access and Monitoring**:

• **Fill ports**: Secure access for tanker truck filling, bollard protection
• **Vapor recovery**: Required in California, separate piping system
• **Monitoring wells**: Interstitial monitoring, groundwater monitoring
• **Electrical**: Leak detection sensors, submersible pumps (turbine pumps inside tanks)

**Island Configuration**:

• **Size**: Typically 4-6 ft wide × 20-50 ft long
• **Height**: 6-8 inches above pavement (per CBC Section 406.6.3—protect dispensers from vehicle impacts)
• **Spacing**: 12-14 ft between parallel islands (vehicle access)
• **Layout**: Angled islands improve traffic flow and capacity

**Concrete Construction**:

• **Slab thickness**: 8-12 inches reinforced concrete
• **Reinforcement**: #4 or #5 rebar at 12" o.c. each way minimum, top and bottom layers
• **Concrete strength**: 3,500-4,000 psi
• **Perimeter curb**: 6-8 inch tall curb, integral with slab or separate formed curb

**Foundation**:

• **Base course**: 6-8 inches compacted aggregate base
• **Subgrade**: Compacted native soil or engineered fill (95% compaction minimum)
• **Frost protection**: Highland rarely freezes, but minimum 12 inch depth below grade recommended

**Dispenser Anchorage**:

• Fuel dispensers anchored to island slab
• **Anchor bolts**: 3/4" or 1" diameter, 12-18" embedment
• Design for dispenser weight plus accidental impact loads
• **Bollards** or protective posts required around dispensers (per Fire Code and petroleum regulations)

**Underground Utilities**:

• Fuel piping from USTs to dispensers
• Electrical conduits for dispenser power and payment systems
• Vapor recovery piping
• All embedded in island slab or beneath island
• **Flexible connections**: Accommodate settlement, thermal movement, seismic displacement

**Containment Sumps**:

• Required under dispensers and at pipe connections
• Containment sumps detect leaks and prevent soil contamination
• Must be structurally supported within island construction

**Impact Resistance**:

• Islands designed for vehicle impact (errant vehicles, careless drivers)
• Reinforcement prevents slab breakup
• Bollards protect dispensers from direct impact
• Some jurisdictions require crash-rated bollards

**Pavement Loading**:

• **Passenger vehicles**: 4,000-8,000 lbs, repetitive loading
• **Fuel delivery trucks**: Up to 80,000 lbs gross vehicle weight
• **Pavement design**: Must resist rutting, cracking, and failure under repetitive heavy loads

**Asphalt Pavement Design** (Most Common):

• **Asphalt thickness**: 4-6 inches (residential access), 6-8 inches (heavy truck traffic)
• **Base course**: 6-12 inches aggregate base (Class II AB), compacted to 95%
• **Subgrade**: Compacted native soil to 90-95% relative compaction
• **Total section**: Typically 12-18 inches
• **R-value testing**: Soils tested for bearing capacity (R-value), used in pavement design calculations
• **Typical cost**: $5-$9 per sq ft

**Concrete Pavement Design**:

• Used for high-traffic areas, tanker truck routes, drive-over tank areas
• **Slab thickness**: 6-8 inches reinforced concrete
• **Reinforcement**: WWF (6×6-W2.9×W2.9) or #4 rebar at 18" o.c.
• **Joints**: 15-20 ft spacing, saw-cut control joints
• **Concrete strength**: 3,000-3,500 psi
• **Typical cost**: $8-$14 per sq ft

**Highland Soil Considerations**:

• **Soil type**: Alluvial deposits, decomposed granite in elevated areas
• **Bearing capacity**: Typically moderate to good (R-value 30-60)
• **Expansive soils**: Some areas may have expansive clay—requires deeper base course or soil stabilization
• **Geotechnical investigation**: Recommended to determine pavement section design

**Building Type**:

• **Size**: 2,000-5,000 sq ft typical
• **Construction**:
• **Wood frame** (most economical): 2×6 studs, engineered trusses
• **Steel frame**: Pre-engineered metal building or conventional steel
• **Masonry**: CMU or tilt-up concrete (larger stores)

**Structural Requirements**:

• **Foundation**: Slab-on-grade with thickened edges (18-24" deep) typical
• **Floor loading**: 40-60 psf for retail areas, 125 psf for storage
• **Roof loading**: 20 psf live + snow load + dead load
• **Lateral system**: Shear walls or moment frames for seismic and wind

**Special Considerations**:

• **Refrigerated walk-in coolers**: Heavy floor loading (300-500 psf), requires special footing or slab reinforcement
• **Shelving**: High-density merchandise creates higher-than-code floor loads in aisles
• **Food service**: If restaurant or hot food service, consider grease interceptor (affects site utilities)
• **Signage**: Pylon signs (30-60 ft tall) require separate structural design and foundation

**Example - Canopy Column in Highland**:

• Wind uplift: 25 psf
• Tributary area: 1,200 sq ft (30' × 40' column spacing)
• Total uplift: 30,000 lbs
• Dead load: 35 psf × 1,200 sq ft = 42,000 lbs
• Load combination (0.6D - 1.0W): 0.6 × 42k - 1.0 × 30k = **-4,800 lbs (uplift)**
• Design anchor bolts for 4,800 lbs tension plus shear

**Example - 50-ft Pylon Sign in Highland**:

• Sign face: 12 ft × 20 ft (both sides) = 480 sq ft total
• Wind load: 25-35 psf (varies with height and exposure)
• Total wind force: ~12,000-15,000 lbs
• Overturning moment at base: 300,000-450,000 ft-lbs
• Footing: 8' × 8' × 5' deep reinforced concrete, 15-20 tons, resists overturning

**Structural Engineering Services**:

• **Small gas station** (2-island canopy, no building): $8,000-$12,000
• **Medium gas station** (4-6 island canopy, small convenience store): $12,000-$20,000
• **Large gas station/truck stop** (large canopy, 3,000-5,000 sq ft store, car wash): $20,000-$35,000
• **Branded station with proprietary canopy**: $10,000-$18,000 (reduced scope if canopy pre-engineered)

**Scope typically includes**:

• Fuel canopy structural design (or foundation design for pre-engineered canopy)
• Convenience store building design
• Fuel dispenser island design
• UST installation support (excavation, backfill, loading analysis)
• Pylon sign design
• Foundation design for Highland soil conditions
• Pavement loading analysis (coordination with civil engineer)
• Seismic and wind analysis
• Construction documents and engineer's seal
• Permit support and plan check response

**Additional Services**:

• Geotechnical investigation: $3,000-$8,000 (separate consultant)
• Civil engineering (site grading, utilities, drainage, paving): $15,000-$35,000 (separate consultant)
• MEP engineering (mechanical, electrical, plumbing): $15,000-$30,000 (separate consultant)
• Petroleum engineer or UST installer: $10,000-$25,000 (separate consultant)

**New Gas Station Construction** (complete facility):

• **Small station** (2-4 islands, 2,000 sq ft store): $1.2M-$2.0M
• **Medium station** (4-6 islands, 3,000 sq ft store): $1.8M-$3.2M
• **Large station/truck stop** (6-8 islands, 5,000 sq ft store, car wash): $3.0M-$5.5M

**Fuel Canopy**:

• **Steel canopy** (standard design): $45-$75 per sq ft
• **Branded canopy** (Chevron, Shell, etc.): $60-$90 per sq ft
• **Example**: 100' × 40' canopy (4,000 sq ft) = $180,000-$300,000

**Underground Storage Tanks**:

• **Tanks** (double-walled fiberglass): $18,000-$35,000 each (10,000-20,000 gallon capacity)
• **Excavation and installation**: $30,000-$80,000 (depends on number of tanks, soil conditions, depth)
• **Piping and sumps**: $20,000-$50,000
• **Leak detection and monitoring**: $15,000-$30,000
• **Total UST system**: $150,000-$350,000 for typical 4-5 tank installation

**Fuel Dispensers and Equipment**:

• **Fuel dispensers**: $15,000-$25,000 each
• **6-dispenser installation** (12 fueling positions): $90,000-$150,000
• **Payment system**: $20,000-$40,000
• **Vapor recovery**: $10,000-$20,000

**Dispenser Islands**:

• **Concrete islands**: $200-$350 per linear foot (includes concrete, reinforcement, curb, bollards)
• **Example**: 3 islands × 40 ft each = 120 LF = $24,000-$42,000

**Convenience Store Building**:

• **Wood frame**: $180-$250 per sq ft
• **Steel frame**: $200-$280 per sq ft
• **Example**: 3,000 sq ft store = $540,000-$750,000

**Site Work**:

• **Grading**: $8-$18 per cubic yard
• **Asphalt paving**: $5-$9 per sq ft
• **Concrete paving**: $8-$14 per sq ft
• **Utilities** (water, sewer, electric, gas): $80,000-$200,000
• **Landscaping**: $20,000-$60,000
• **Site lighting**: $40,000-$80,000

**Pylon Sign**:

• **30-40 ft sign**: $30,000-$60,000
• **50-60 ft sign**: $60,000-$100,000
• Includes structure, foundation, faces, electrical, installation

**Highland-Specific Factors**:

• Labor costs moderate compared to coastal California
• Material delivery from Inland Empire suppliers (San Bernardino, Ontario, Riverside)
• Water and sewer connection fees: Contact City of Highland Public Works
• Utility extension costs can be significant for outlying sites

**City of Highland Fees** (2025 rates):

• **Building permit**: Based on valuation, typically $20-$30 per $1,000 construction value
• **Plan check**: 65% of building permit fee
• **UST permit**: $2,000-$5,000 (State Fire Marshal + local fire)
• **Plumbing permit**: $1,500-$3,000
• **Mechanical permit**: $1,200-$2,500
• **Electrical permit**: $2,000-$4,000

**Other Agency Fees**:

• **California State Fire Marshal**: UST permit fee ($1,500-$3,000)
• **San Bernardino County Environmental Health**: Monitoring and compliance fees ($500-$1,500)
• **Air Quality Management District**: Vapor recovery certification ($800-$1,500)
• **Regional Water Quality Control Board**: Stormwater NPDES permit ($2,000-$5,000)

We've completed numerous structural engineering projects in Highland and San Bernardino County:

• Petroleum retail facilities
• Heavy commercial vehicle facilities
• Automotive service centers
• Large-span canopy structures
• Mixed-use retail and service developments

**We understand**:

• Highland's soil conditions (alluvial and decomposed granite)
• City of Highland Building & Safety Department processes
• San Bernardino County Fire Department petroleum facility requirements
• State Fire Marshal UST permitting
• Seismic Design Category D requirements for Inland Empire
• Wind exposure at Highland's elevation and exposure
• Integration with Highland's commercial development standards

**Phase 1: Initial Consultation (Free)**

• Discuss your gas station concept and brand requirements
• Review site and access
• Identify key structural challenges
• Provide preliminary scope and fee estimate

**Phase 2: Structural Design (6-8 weeks)**

• Site visit and survey review
• Geotechnical report analysis
• Fuel canopy structural design (or foundation design for pre-engineered canopy)
• Convenience store building design
• Dispenser island and pavement loading analysis
• UST excavation and installation support
• Pylon sign design
• Foundation design for Highland soil conditions
• Wind and seismic analysis per CBC and ASCE 7-22
• Coordination with civil, MEP, and petroleum engineers

**Phase 3: Construction Documents (2-3 weeks)**

• Structural plan sheets
• Foundation and footing details
• Canopy framing plans and connection details
• Dispenser island details
• Sign structure and foundation
• Structural calculations
• Special inspection requirements
• Engineer's seal and signature

**Phase 4: Permit Support (Ongoing)**

• Submit to City of Highland Building & Safety
• Coordinate with Fire Marshal and State Fire Marshal
• Respond to plan check comments
• Support through permit approval (typically 10-16 weeks)

**Phase 5: Construction Phase Services**

• Review shop drawings (canopy, sign structures)
• Answer contractor RFIs
• Site visits during critical phases (foundations, canopy erection, UST installation)
• Final inspection support

**Challenge**:

• Site located near I-210 with high wind exposure
• Shallow bedrock in some areas (unexpected during initial investigation)
• Tight schedule to meet franchise opening deadline
• State Fire Marshal permitting delays

**Result**:

• Project permitted through City of Highland and State Fire Marshal in 13 weeks
• Structural construction completed on schedule
• All inspections passed without issues
• Station opened on target date
• Facility has operated successfully for 3+ years with no structural problems

**Our services include:**

• Fuel canopy structural design
• Underground storage tank installation support
• Dispenser island and pavement design
• Convenience store building engineering
• Pylon sign structures
• Foundation design for Highland soil conditions
• Wind and seismic analysis
• Multi-agency permit coordination
• Construction phase support

**Q: How big are gas station foundations?**

• **Canopy column footings**: 4-6 ft square × 3-4 ft deep typical
• **Pylon sign foundation**: 6-10 ft square × 4-6 ft deep for 40-60 ft signs
• **Convenience store**: Slab-on-grade with 18-24" deep perimeter thickened edge

**Comprehensive Guides:**

• Complete Commercial & Industrial Structural Engineering Guide

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