Report No.: CCEER-03-1

Title: User's Manual for SPMC v. 1.0: A Computer Program for Moment-Curvature Analysis of Reinforced Concrete Sections with Interlocking Spirals

Authors: N. Wehbe and M. Saiidi

Date: May 2003

Sponsoring Agency: California Department of Transportation (CalTrans)

Performing Organization:
Department of Civil Engineering/258
University of Nevada, Reno
Reno, NV 89557


This report constitutes the user's manual for SPMC v. 1.01. SPMC v. 1.01 is a computer program for moment-curvature analysis of reinforced concrete sections with interlocking spirals. The program was written in C + + and compiled using TURBO C+ + 4.5 (for DOS) from Borland International.

The program consists of one execution file called "SPMClO.EXE" and creates one output file. The output file name is specified by the user. Data input can be either interactive, i.e. the user is prompted to enter the data during program execution, or through an input data file. The input data file is an ASCII file that can be created and edited using any ASCII text editor. When the interactive data input mode is selected, the user has the option to save the input data in an ASCII file. The name of the file containing the input data is specified by the user.

Three examples illustrating the use of SPMC v. 1.01 are also included in this manual. Each example includes both input and output data.

Some of the features of SPMC v. 1.01 are

  • Analysis of single, double, and triple spiral cross sections
  • Analysis of sections with square, oblong, or chamfered ends
  • Analysis of confined and unconfined cross sections
  • Steel layers of different properties in the same cross section can be accommodated
  • The moment-curvature analysis of a reinforced concrete cross section can be performed for several axial loads during the same run
  • The effect of crushing of the cover concrete on the section behavior is accounted for in the analysis
  • The option of modeling strain hardening of steel using a parabolic profile
  • The option of using a bi-linear curve to model the stress-strain relationship of cover concrete that is confined within fiber reinforced plastic jackets
  • Continued data output past the points of rupture of reinforcing steel
  • Up to 50 steel layers can be specified in a section