Plans and calculations shall be submitted, signed and stamped by a Registered Professional Engineer familiar with Railroad loadings and who is licensed in the state where the shoring system is intended for use. Shoring design plans and calculations shall be in English units. If Metric units are used, all controlling dimensions, elevations, design criteria assumptions, and material stresses shall be expressed in dual units, with English units to be in parentheses. Information shall be assembled concerning right-of-way boundary, clearances, proposed grades of tracks and roads, and all other factors that may influence the controlling dimensions of the proposed shoring system. See section 10 for additional requirements.
Sufficient information shall be shown on the plans in the form of profiles, cross sections and topographical maps to determine general design and structural requirements. Field survey information of critical or key dimensions shall be referenced to the centerline of track(s) and top of rail elevations. Existing and proposed grades and alignment of tracks and roads shall be indicated together with a record of controlling elevation of water surfaces or ground water. Show the location of existing/proposed utilities and construction history of the area which might hamper proper installation of the piling, soldier beams, or ground anchors.
Geotechnical Report shall provide:
a. Elevation and location of soil boring in reference to the track(s) centerline and top of rail elevations.
b. Classification of all soils encountered.
c. Internal angle of soil friction.
d. Dry and wet unit weights of soil.
e. Active and passive soil coefficients, pressure diagram for multiple soil strata.
f. Bearing capacity and unconfined compression strength of soil.
g. Backfill and compaction recommendations.
h. Optimum moisture content of fill material.
i. Maximum density of fill material.
j. Minimum recommended factor of safety.
k. Water table elevation on both sides of the shoring system.
l. Dewatering wells and proposed flownets or zones of influence.
m. In seismic areas, evaluation of liquefaction potential of various soil strata.
All design criteria, temporary and permanent loading must be clearly stated in the design calculations and on the contract and record plans. Temporary loads include, but are not limited to: construction equipment, construction materials and lower water levels adjoining the bulkhead causing unbalanced hydrostatic pressure. Permanent loads include, but are not limited to: future grading and paving, Railroads or highways, structures, material storage piles, snow and earthquake. The allowable live load after construction should be clearly shown in the plans and painted on the pavements behind the bulkheads or shown on signs at the site and also recorded on the record plans. Some of the loads are:
a. Live load pressure due to E80 loading for track parallel to shoring system.
b. Live load pressure due to E80 loading for track at right angle to shoring system.
c. Other live loads.
d. Active earth pressure due to soil.
e. Passive earth pressure due to soil.
f. Active earth pressure due to surcharge loads.
g. Active pressure due to sloped embankment.
h. Dead load.
j. Longitudinal force from live load.
k. Centrifugal forces.
o. Stream flow pressure.
p. Ice pressure.
Drainage. (AREMA 188.8.131.52)
a. The drainage pattern of the site before and after construction should be analyzed and adequate drainage provisions should be incorporated into the plans and specifications. Consideration should be given to groundwater as well as surface drainage.
b. Drainage provisions for backfill should be compatible with the assumed water conditions in design.
Structural design calculations.
a. List all assumptions used to design the temporary shoring system.
b. Determine E80 live load lateral pressure using the Boussinesq strip load equation. See Figure 2 (PDF File) which illustrates Plan Number 710001 “LIVE LOAD PRESSURE DUE TO COOPER E80”.
c. Computerized calculations and programs must clearly indicate the input and output data. List all equations used in determining the output.
d. Example calculations with values must be provided to support computerized output and match the calculated computer result.
e. Provide a simple free body diagram showing all controlling dimensions and applied loads on the temporary shoring system.
f. Calculated lateral deflections of the shoring and effects to the rail system must be included. See section 8, Part 6. Include the elastic deflection of the wall as well as the deflection due to the passive deflection of the resisting soil mass.
g. Documents and manufacturer’s recommendations which support the design assumptions must be included with the calculations.