STRUCTURAL BRIDGE AUDIT • 200T-350T TBM SHIELD • DOT SPECIAL PROVISIONS

TBM Shield & Main Bearing Bridge Shoring Audit

Structural engineering checklist for superheavy TBM shields and drive assemblies crossing highway spans: temporary falsework shoring, box culvert steel jumper plating, bolster articulation locks, and real-time girder strain gauge monitoring.

01 Critical Structural Bridge & Shoring Checkpoints Select verified criteria

Phase 1: State DOT Structural Bridge Rating Analysis

PE-Stamped Bridge Structural Load Rating: Finite Element Analysis (FEA) completed for every bridge span along designated route; maximum bending moments and shear stresses certified below 85% operating capacity.

Single-Vehicle Solo Straddle Crossing Mandate: Bridge crossing permit stipulates zero other vehicular traffic on bridge structure; rolling roadblock deployed to isolate bridge deck entirely during 5 mph transit.

Centerline Straddle Alignment Tolerance (±100mm): Driver and steerable platform operators enforce exact alignment over center girders with pilot car laser guidance to balance torsional pier moments.

Phase 2: Temporary Steel Shoring & Culvert Jumper Plating

Mid-Span Modular Steel Shoring Towers Installed: Temporary 100t-rated hydraulic shoring posts erected under weak steel/timber spans; pre-stressed hydraulic jacks pre-load bridge stringers to eliminate live deflection.

Box Culvert Steel Jumper Plating (2.0" A36 Plate): All roadway culverts plated with minimum 2-inch certified structural steel plates spanning 3.0 meters beyond culvert wingwalls with timber leveling berms.

Under-Bridge Clearance & Foundation Settlement Survey: Geotechnical laser survey confirming shoring footings rest on compacted crushed stone pads (≥ 350 kPa bearing capacity); zero ground pumping.

Phase 3: Platform Bolster Locks & Deflection Telemetry

Bolster Articulation Lockout Engagement: Hydraulic turntable bolster slewing locks mechanically pinned during bridge traversal to prevent transverse load shifts while straddling span.

Hydraulic Pressure Transducer Equalization: Platform hydraulic suspension monitored via in-cab telemetry; cross-axle pressure variation strictly maintained within ±5% delta.

Live LVDT Deflection & Strain Gauge Monitoring: Real-time bridge deflection sensors monitored by State DOT bridge engineers at span midpoint; transit halted if girder deflection exceeds L/800.

BRIDGE CROSSING AUDIT STATUS

ALL SHORING VERIFIED • CROSSING CLEARED

Bridge Shoring Compliance Score 100% 9 of 9 checkpoints verified

Span Transit Speed: ≤ 5.0 mph Constant Crawl

Max Deflection Limit: ≤ L / 800 (AASHTO Criteria)

Traffic Isolation: 100% Total Deck Clearance

DOT PE Inspector: On-Site Sign-Off Required

AASHTO Manual for Bridge Evaluation • LRFR AUDIT v2026.4

Punching Shear & Deck Plating

Superheavy multi-axle platform tires exert high localized contact pressures on concrete bridge decks. Steel distributor plates or heavy timber mats bridge the wheel loads directly across longitudinal steel stringers, mitigating deck punching shear.

Pre-Loaded Hydraulic Shoring

Standard timber falsework can settle when subjected to 350-ton dynamic loads. High-capacity hydraulic shoring cylinders pre-stress the bridge girders prior to crossing, eliminating sudden mid-span deflection transients.

Live Strain Gauge Telemetry

Optical strain gauges adhered to girder bottom flanges transmit live microstrain (με) readings to engineers stationed at the bridge abutment, validating FEA structural models against real-time wheel load distribution.

Need Automated Bridge Shoring & Permit Routing in Your TMS?

Exspeedite Heavy Haul TMS manages bridge division FEA models, coordinates temporary shoring contractors, and maintains digital permit compliance logs for mega-infrastructure superloads.

View TBM Transport Manual