What this type of data looks like
Inspection data for bridge disease identification comes primarily from three sources: on-site inspection reports, original disease detection records, and aerial image annotation documents. Data update frequency follows inspection cycles, with new archived documents generated after each completed inspection. Single documents typically include inspection time, bridge ID, disease location, disease type, detection values, on-site photo attachments, and other content. Fields cover professional engineering terms, and units include millimeters, meters, megapascals, and other commonly used engineering units. Most document structures follow a title-sectioned format. Some inspection reports include embedded tables and high-resolution photos, leading to overall high layout complexity.
What constraints do these characteristics impose on the document parsing and chunking link?
Mixed multi-format layouts in inspection documents require the parsing step to support extraction of tables and embedded photos from complex PDFs, to avoid losing key disease information. When chunking professional engineering terms and long-form disease descriptions, context must be preserved to prevent term splitting that disrupts subsequent judgment work. Large archived files with many pages increase parsing time, so longer timeout thresholds must be supported. Structured inspection field distribution requires chunking rules to align with the document's title-section structure, ensuring each chunk corresponds to a complete inspection unit or disease record. Document sizes vary widely across different inspection cycles, so sufficient upload and parsing space must be reserved to avoid parsing failures caused by file size limits.
Configuration Settings
Reference only; verify against the target FastGPT release and deployment documentation.
| Configuration Item | Recommended Value | Rationale |
|---|---|---|
chunkSize | 800–1200 characters | Matches the average length of single-segment disease descriptions in bridge inspection documents, avoiding splitting complete context of professional engineering terms |
chunkSplitter | By paragraph + title | Aligns with the title-sectioned structure of inspection documents, ensuring each chunk corresponds to a complete inspection point or disease record |
customPdfParse | Enabled | Supports extraction of embedded tables and photo OCR text from PDFs, adapting to the complex layout of inspection reports |
PARSE_FILE_TIMEOUT_SECONDS | 300–600 seconds | Adapts to parsing time for large inspection reports with multiple pages of photos, avoiding parsing failures due to timeout |
UPLOAD_FILE_MAX_SIZE | 500 MB | Compatible with the size limit of large annual bridge inspection archive files |
chunkSettingMode | Manual configuration | Allows adjustment of chunking rules for professional documents used in bridge disease identification, adapting to context retention requirements for engineering terms |
Three Common Configuration Errors
- Phenomenon: Upload a bridge inspection PDF and receive a parsing failure status code or 504 timeout prompt. Cause:
PARSE_FILE_TIMEOUT_SECONDSwas not adjusted. The default timeout value is insufficient for large reports containing multiple on-site photos. - Phenomenon: The large model output cannot match photo annotation information in the inspection report, and can only recognize plain text content. Cause:
customPdfParsewas not enabled. The default parsing only extracts basic plain text, and does not retain OCR results from embedded photos. - Phenomenon: Chunk results contain broken professional terms, such as "prestressed tendon corrosion" split into two separate chunks. Cause:
chunkSizeis set too small, forcing long terms or paragraphs to split and losing context association.
How to Verify Correct Configuration
- Upload a typical bridge inspection PDF report, check if the parsed text includes embedded tables and OCR content from photos, to confirm
customPdfParseis enabled. - Check the background logs of the parsing task, confirm that the
PARSE_FILE_TIMEOUT_SECONDSconfiguration value matches the actual task duration, and there are no timeout error records. - Randomly sample chunk results, check that professional engineering terms are fully retained in a single chunk, to confirm
chunkSizeandchunkSplitterconfigurations meet expectations. - Call the knowledge base file collection creation API, specify
customPdfParseas true in the request parameters, verify that the parsing behavior matches the preset rules.
Note: The configuration values listed are common starting points. Adjust them based on your own specific samples.
Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-28.