PLAXIS 3D Geotech Model Creation

Job ID: 40394053

Budget: $30 – $250 AUD

**PLAXIS 3D Model Setup and Analysis for Shallow Excavation (Capstone Project)**

I require assistance in developing a PLAXIS 3D model for a shallow excavation as part of a civil engineering capstone project. The purpose of this model is to validate an existing Excel-based analytical model predicting wall deflection and ground settlement.

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**Project Scope**

The model represents a rectangular excavation for an underground car park.

* Excavation depth: **H = 2.5 m**
* Excavation geometry (baseline): **20 m × 30 m**
* Retaining wall thickness: **0.30 m**
* Embedment ratios:

* **D/H = 1.0 (D = 2.5 m)**
* **D/H = 1.5 (D = 3.75 m)**
* Excavation to be modelled in **0.5 m stages**
* Groundwater assumed deep (no influence)

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**Analysis Requirements (12 Cases)**

The model should include and analyse the following scenarios:

**Group A – Soil stiffness × embedment (6 cases)**

* Soil stiffness levels: **E ≈ 10, 25, 50 MPa**
* Embedment ratios: **D/H = 1.0 and 1.5**
* Cantilever wall condition

**Group B – Plan geometry / corner effects (3 cases)**

* 20 × 20 m (square)
* 20 × 30 m (baseline)
* 20 × 50 m (elongated)
* Evaluate corner vs mid-wall settlement

#**Group C – Support conditions (3 cases)**

* Cantilever (baseline)
* Single strut near top (~0.5 m depth)
* Base slab support (box action)

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**Soil Modelling**

* Use **Mohr–Coulomb model** for all cases (minimum requirement)
* Optional: HSsmall model for selected cases if available
* Soil parameters should be selected to reflect approximate stiffness values (10, 25, 50 MPa)

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**Outputs Required**

For each case:

* Maximum wall deflection (**δh,max**)
* Normalised deflection (**δh/H**)
* Maximum settlement (**Smax**)
* Normalised settlement (**Smax/H**)
* Settlement profiles:

* Mid-wall
* Corner
* Corner reduction factor (**Rc** for geometry cases)

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**Deliverables**

* PLAXIS 3D model file
* Results summary (Excel or table format)
* Plots:

* Wall deflection vs depth
* Settlement vs distance from wall
* Brief explanation of modelling assumptions

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**Important Notes**

* This is an academic validation study — accuracy and consistency are more important than complexity
* Model should remain simple and aligned with the provided parameters (no unnecessary features)
* Results must follow expected geotechnical trends (stiffness ↑ → movement ↓, etc.)

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**Ideal Freelancer**

* Strong experience with PLAXIS 3D
* Background in geotechnical excavation modelling
* Ability to clearly extract and present results

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The goal is to produce a reliable FEM model that can be directly compared with an existing analytical model for validation purposes.