GB 50497-2019 Interpretation

GB 50497-2019 Interpretation

1. Standard Overview

1.1 Basic Information

Item	Content
Standard Number	GB 50497-2019
Standard Name	Technical Standard for Monitoring of Building Foundation Pit Engineering
Issuing Authority	Ministry of Housing and Urban-Rural Development of the People’s Republic of China
Implementation Date	2020-XX-XX
Replaces	GB 50497-2009
Scope	Monitoring of building foundation pit engineering

1.2 Standard Structure

GB 50497-2019 consists of the following main chapters:

1. General Provisions
2. Terms and Symbols
3. Basic Requirements
4. Monitoring Projects
5. Monitoring Point Layout
6. Monitoring Methods and Precision
7. Monitoring Frequency
8. Monitoring Warning
9. Monitoring Results and Information Management

2. Key Provisions Interpretation

2.1 Monitoring Level (Article 3.0.3)

The standard divides foundation pit monitoring into three levels:

Level	Foundation Pit Depth	Surrounding Environment	Geological Conditions
Level I	≥ 20m or complex	Very sensitive	Complex
Level II	10-20m	Sensitive	Moderate
Level III	< 10m, simple	General	Simple

AI Interpretation:

Level I monitoring applies to:

• Deep foundation pits (≥20m) or with complex geological conditions
• Adjacent to important buildings, subways, or historical relics
• In soft soil, karst, or other complex geological conditions

Level II monitoring applies to:

• Medium-depth foundation pits (10-20m)
• Adjacent to general buildings or pipelines
• In relatively simple geological conditions

Level III monitoring applies to:

• Shallow foundation pits (<10m)
• No sensitive surrounding environment
• In simple geological conditions

2.2 Monitoring Items (Article 4.0.1)

The standard specifies mandatory and optional monitoring items:

Mandatory Monitoring Items

Monitoring Item	Level I	Level II	Level III
Enclosure wall (pile) top horizontal displacement	●	●	○
Enclosure wall (pile) top vertical displacement	●	●	○
Deep horizontal displacement	●	○	-
Support axial force	●	○	-
Anchor stress	●	○	-
Underground water level	●	●	○
Surface settlement	●	●	○
Building settlement	●	●	○
Building inclination	●	○	-
Building cracks	●	○	-
Pipeline settlement	●	●	○
Base slab heave	●	○	-

Note: ● Mandatory, ○ Optional, - Not required

2.3 Monitoring Precision (Article 6.0.2)

Monitoring Item	Instrument	Precision
Horizontal displacement	Total station, GNSS	±1.0mm
Vertical displacement	Level, total station	±0.5mm
Deep horizontal displacement	Inclinometer	±0.1mm/500mm
Support axial force	Strain gauge, load cell	±1%FS
Underground water level	Water level meter	±5mm
Building settlement	Level, total station	±0.5mm
Building inclination	Total station	±1/10000
Crack width	Crack gauge	±0.01mm

2.4 Monitoring Frequency (Article 7.0.3)

Construction Stage	Level I	Level II	Level III
Before excavation	1d/time	1d/time	1d/time
During excavation	2d/time	1d/time	1d/2-3times
Support installation	2d/time	1d/time	1d/2-3times
Base slab pouring	1d/time	1d/2times	1d/3times
After completion	1d/2-3times	1d/3-7times	1d/7times

3. Practical Application

3.1 Monitoring Scheme Design

When designing a monitoring scheme based on GB 50497-2019, the following steps should be followed:

1. Determine Monitoring Level: Based on foundation pit depth, surrounding environment, and geological conditions
2. Select Monitoring Items: Based on monitoring level and engineering characteristics
3. Design Point Layout: Based on monitoring items and engineering conditions
4. Select Instruments: Based on precision requirements and site conditions
5. Determine Frequency: Based on construction stage and monitoring level
6. Set Warning Values: Based on design requirements and standard provisions

3.2 Warning Value Setting

Warning values should be set based on the following principles:

Monitoring Item	Warning Value Basis	Typical Range
Enclosure wall top displacement	60-80% of design value	30-50mm
Deep horizontal displacement	60-80% of design value	50-70mm
Surface settlement	60-80% of design value	30-50mm
Building settlement	60-80% of design value	15-25mm
Building inclination	60-80% of design value	1/500

4. AI-Assisted Interpretation

4.1 Intelligent Monitoring Scheme Generation

Based on GB 50497-2019, AI can automatically generate monitoring schemes:

Input: Foundation pit depth, surrounding environment, geological conditions
↓
AI Analysis: Determine monitoring level, select monitoring items
↓
Output: Monitoring scheme (point layout, instrument selection, frequency)

4.2 Intelligent Warning Analysis

AI can automatically analyze monitoring data and issue warnings:

Input: Monitoring data, warning values
↓
AI Analysis: Trend analysis, anomaly detection, warning judgment
↓
Output: Warning information, cause analysis, suggestions

5. Related Documents

• GB 50911-2013 Interpretation
• JGJ 8-2016 Interpretation
• CJJ/T 202-2013 Interpretation
• Deep Foundation Pit Monitoring Scenario

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