What Data for This Category Looks Like
The data for railway and highway intelligent due diligence reports comes primarily from official documents including project completion archives, daily maintenance ledgers, road administration inspection records, and project feasibility study reports. Update cycles vary by document type: completion documents are archived and updated once when a project finishes. Maintenance and inspection documents update monthly, quarterly, or when events occur. Document structures include mixed-format content: long technical analysis paragraphs, structured bills of quantities tables, location fields with stake numbers and mileage, plus specialized fields such as materials, load capacity, and maintenance cycles. Units use engineering-specific measurements including kilometers, cubic meters, tons, and inspection frequency (times/quarter).
Constraints for Document Parsing and Chunking
The mixed-format structure of railway and highway documents requires parsing tools to handle both long technical text paragraphs and complex structured tables. When working with merged cells or cross-page continuous bills of quantities, parsing logic must avoid splitting logical table units. Specialized fields such as stake numbers and mileage have continuous location attributes. Chunking processes must retain contextual connections between these fields. This prevents splitting stake number information in the same paragraph from subsequent technical descriptions into separate chunks. Engineering-specific units bind directly to numerical values. Parsing logic must preserve this association to avoid errors where values and units become separated. Different document update cycles create distinct requirements for batch parsing concurrency configurations. Frequently updated maintenance documents need real-time parsing queues. Low-frequency archived documents can use offline batch processing workflows.
How to Set Configurations
| Configuration Item | Recommended Setting | Rationale |
|---|---|---|
PARSE_ENABLE_OCR | Enable for scanned PDFs, disable for non-scanned documents | Railway and highway documents contain large numbers of scanned completion drawings and maintenance ledgers. Enabling OCR restores table and text content from scanned documents. Disabling it for non-scanned documents saves parsing resources |
TABLE_PARSE_STRATEGY | Merge cross-page continuous tables, retain header associations | Railway and highway bills of quantities often span multiple pages. This configuration merges cross-page tables into complete logical units, avoiding splitting headers from their corresponding data rows |
CHUNK_SIZE | 800–1200 characters | Railway and highway documents contain long technical paragraphs and structured fields. This range balances contextual integrity and retrieval accuracy, avoiding splitting specialized term combinations or stake number location information |
PARSE_TIMEOUT_SECONDS | 600 seconds | Large completion documents may contain hundreds of pages. A 600-second timeout setting covers the full parsing process, preventing parsing tasks from being interrupted by timeouts |
CHUNK_OVERLAP | 100–150 characters | Retain overlapping content between adjacent chunks. This ensures cross-chunk associated information such as stake numbers and technical parameters is not truncated, improving retrieval recall accuracy |
UPLOAD_FILE_MAX_SIZE | 1000 MB | Single railway and highway project completion documents may include multiple attachments. This setting supports large-scale batch file uploads for parsing |
The parameter values provided on this page are common recommended starting points for configuration. Actual values are affected by material format, data volume, and business rules. Specific issues require individual analysis. It is recommended to test on your own samples before finalizing settings.
Three Common Configuration Errors
- Issue: When uploading a single railway and highway completion document that exceeds the default size, the interface returns a
413 Request Entity Too Largeerror. Cause: TheUPLOAD_FILE_MAX_SIZEconfiguration was not adjusted. The default upload limit does not cover the upload requirements of large multi-attachment combined documents. - Issue: After parsing scanned road administration inspection records or completion ledgers, table data appears misaligned or some fields are empty. Cause: The
TABLE_PARSE_STRATEGYconfiguration for cross-page merging and header association was not enabled. The default parsing logic cannot recognize cross-page bills of quantities and merged cell structures common in railway and highway documents. - Issue: After uploading a document, the parsing result only returns a small number of text fragments, or professional technical content cannot be retrieved. Cause: The
CHUNK_SIZEconfiguration was not adjusted based on document type. An overly small chunk length causes specialized terms and stake number location information to be split. OrPARSE_ENABLE_OCRwas not enabled for scanned documents, preventing scanned content from being properly recognized.
How to Verify Correct Configuration
- Upload a typical railway and highway document, such as a single-page scanned maintenance ledger or multi-page completion PDF. Check the parsing task status logs to confirm there are no timeout or format error prompts.
- Randomly extract chunks from the parsed content. Verify that specialized fields such as stake numbers and mileage are fully associated with their corresponding units, with no splitting or separation.
- Test batch uploads of multiple different types of railway and highway documents. Confirm that the parsing queue can assign processing priorities based on document update cycles.
- View the parsing configuration panel. Confirm that core parameters such as
PARSE_ENABLE_OCRandTABLE_PARSE_STRATEGYmatch the current document type.
Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-14.