What data for this category looks like
Infrastructure engineering investment research data mainly comes from industry standard PDF drawings, construction log Excel files, cost list CSV files, bidding announcement Word documents, and similar sources. Update frequency adjusts based on project progress, with monthly or weekly updates during a single project cycle. Most documents follow a fixed chapter structure, including modules such as project overview, bill of quantities, and progress plan. Most fields use dedicated units such as cubic meters and square meters. Some documents include scanned drawings and nested tables.
What constraints do these characteristics impose on document parsing and chunking?
The fixed chapter structure requires parsing tools to retain the original document’s chapter hierarchy, avoiding semantic breaks caused by splicing content across chapters. Nested tables and dedicated engineering units require parsing tools to accurately identify cell associations, preventing misalignment between numerical values and their corresponding units. PDFs containing scanned drawings need support for accurate OCR recognition of vector annotation text, avoiding loss of engineering parameters. Frequently updated project documents need to adapt to batch parsing efficiency requirements, avoiding single-file processing timeouts that disrupt overall progress.
How to configure settings
| Configuration Item | Recommended Setting | Rationale |
|---|---|---|
ocrEnable | Enable for scanned drawing PDFs, disable for plain text PDFs | Infrastructure engineering documents contain large numbers of scanned construction drawings. Enabling OCR extracts engineering parameters and annotation text from these drawings. Disabling OCR for plain text PDFs saves parsing resources. |
chunkSize | 800–1200 characters | Infrastructure engineering documents mostly include long-text bill of quantities and progress descriptions. This range retains the complete semantics of a single engineering data entry, avoiding separation of numerical values and their units after chunking. |
chunkOverlap | 100–150 characters | Retaining overlapping content between adjacent chunks prevents cross-chapter engineering logic from being split and broken, and adapts to the long-paragraph structure of infrastructure documents. |
excelParseMode | Retain original table structure, split cells by row | Infrastructure engineering cost list Excel files mostly use nested tables. Splitting by row retains complete field and unit associations for each quantity takeoff item. |
parseTimeout | 600 seconds | Large infrastructure project PDF drawing files have large file sizes. A 600-second timeout avoids forced interruption of large-file parsing. |
The parameter values provided on this page are all conventional recommendations, used as a starting point for configuration. Actual values are affected by material form, data volume, and business rules. Specific issues require specific analysis. It is recommended to test on your own samples before finalizing settings.
Three common configuration mistakes
- Phenomenon: After uploading a cost list Excel file, the quantity and unit in search results are misaligned. Cause: The
excelParseModewas not configured to split cells by row, resulting in lost association between cells and fields during parsing. - Phenomenon: After parsing a scanned drawing PDF, annotation text from the drawing is not retrieved. Cause: The
ocrEnableconfiguration was not enabled, so OCR extraction of text embedded in images was not triggered. - Phenomenon: A single quantity takeoff item is split into two chunks after chunking, and the unit does not follow the numerical value. Cause: The chunking unit was not clearly defined as characters, and token count was mistakenly used as the chunking basis, resulting in incoherent semantic splitting of Chinese text.
How to confirm correct configuration
- Upload a single scanned construction drawing PDF, check the text content in parsing results, and confirm that OCR-extracted annotation text is complete.
- Upload a cost list Excel file, check the parsed table structure, and confirm that the association between numerical values and units of each quantity takeoff item is not broken.
- Test parsing effects with different chunk lengths, compare semantic integrity after chunking, and adjust values to meet business requirements.
- Upload a large PDF drawing file, check the parsing task status, and confirm that no timeout error occurs.
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.