iProgressiveCollapse
Progressive Collapse Vulnerability / Direct-Removal Scenario Analysis
Load an XLSX model to begin.
1. Model input
2. Threat locations
W, R0 and N may be comma-separated lists. Generated threat locations are stored in Geometry JSON; W is not.
3. Analysis
PC resistance is screening only. One floor: one directly removed vertical support segment may use a two-sided girder bridge or, at a boundary/corner, two intact non-collinear framing branches that each reach an intact lower support. Directly damaged beams remain failed, and failures independently triggered by those damaged beams are allowed to propagate. All floors: the same alternate-path check is applied story by story and can accommodate stacked column damage on one support line; two support lines lost on the same story overwhelm the branch. Direct blast damage, ξ and persistence are unchanged; alternate-path member capacity and gravity demand are not calculated.
4. Client/review files
Display
Display only. Sets the plotted range and may expand automatically to keep the selected state visible.
Display only. Off by default: large gray context clouds are deterministically sampled for responsive plotting; selected-threat traces and all engineering calculations remain exact.
Optional advanced calculations
These calculations are unchanged, but pc85 runs them on demand so the primary Analyze step finishes sooner and uses less peak browser memory.
Physical-range diagnostics deferred until requested.
Targeted hardening comparison deferred until requested.
Selects Q for the consequence plots and Capacity–Consequence metrics.
Structural damage state
Normalized pressure–impulse demand records (ηP, ηI)
Direct-damage candidate selection: Kcₘ(k) and persistent capacity-path intervals
Blast resistance multiplier along the capacity sequence B(cm)
Progressive failure sequence Kcₘ(k,r)
Cumulative consequence along the capacity-path sequence
Shows cumulative final consequence qQ=Q(*)/Qfull for Baseline and both PC strategies, together with the physical cumulative initiating-footprint consequence qD,Q=QD/Qfull. The separate dQ initiating-footprint integration coordinate is retained in the legend (off by default); dQ is not physical direct damage.
Single-event direct and final consequence — ranked by final lost volume
Single-event diagnostic. Each damages-row event is evaluated independently. KD contains the directly failed members; FD=KD plus immediately connected horizontal framing defines the geometric initiating footprint only. Events are ranked by final lost volume. Volume is shown by default; area traces are available from the legend.
Persistent DCS-state consequence Vloss,k(ξ) and ξ-space global envelopes Vlossenv(ξ) — Baseline / PC resistance
This ξ-space plot shows consequence at completed persistent DCS states. Several cumulative member activations can share the same ξ value, so differences inside those tied ξ plateaus are not fully visible here. Use the cumulative qQ(dQ) plot below to compare how Baseline, one-floor PC resistance, and all-floor PC resistance differ during progressive propagation.
Cumulative consequence qQ(dQ) — selected threat and global envelopes
This dQ-space plot preserves the intermediate cumulative propagation states and is the primary propagation-comparison display for comparing how Baseline, one-floor PC resistance, and all-floor PC resistance alter the modeled final failed-member consequence qQ. Here dQ is the normalized initiating-footprint integration coordinate, not physical QD/Qfull. Physical initiating consequence qD,Q and physical amplification αQ=QF/QD are reported separately. Both axes follow Plot focus limit (% of full scale). Display-only; engineering calculations are unchanged.
Capacity–Consequence Interaction Surfaces — selected threat and governing threat
SQ,s(d1,d2)=ξs(d1)qQ,s(d2), with d1=d2=dQ and qQ,s=Qs(*)/Qfull. Baseline uses raw ξ; PC replaces only the first surface ξ ordinate with the second raw-event value. JQ,s=∫ξsddQ·∫qQ,sddQ. Raw DCS ξ and persistence are unchanged. Axes are logarithmic.
Interaction-surface input functions — same selected and governing threats
Shows the exact ξs and qQ,s vectors used by the selected surface. dQ is the integration coordinate and is shown in hover.
Decision Summary
Primary decision-level results only. Use this table first; detailed research and audit quantities remain available below.
No decision summary is available.
Design-Basis Summary
Physical governing cases and PC applicability. The full member-level Design-Basis Damage Envelope remains in Detailed Engineering Diagnostics.
No design-basis summary is available.
Interpret Results — Engineering Decision Guide
Run Analyze, then click Interpret results.
No interpretation generated.
The decision guide uses compact deterministic engineering facts already calculated by iProgressiveCollapse to diagnose initiation versus propagation, identify the residual governing vulnerability, compare mitigation mechanisms, and state the next design checks. The LLM does not receive raw pressure/impulse data and does not recalculate or re-rank the deterministic results. It supports engineering judgment; final acceptance still depends on the project performance objective and verified structural capacity.
Copy Results for AI
Copies deterministic facts, definitions, applicability, and limitations in self-describing Markdown for use with another chatbot or LLM. It excludes raw pressure/impulse data and excludes the generated Engineering Decision Guide.
Detailed Engineering Diagnostics
Full research, audit, and traceability quantities are preserved here. These tables are intentionally collapsed by default so secondary diagnostics do not obscure the primary engineering decision.
Capacity–Consequence Strategy Comparison
No integrated comparison is available.
Disproportionate-Propagation Comparison
No propagation comparison is available.
Design-Basis Damage Envelope
No design-basis threat comparison is available.
Analysis Summary / QA
No analysis loaded.