Skyscraper foundation reinforced with deep mixing method.

Is Your Ground Solid? How Deep Mixing Can Save Your Structures

Lena Voss in Tech & Innovation September 2025 • 4 min read.

"A Simple Guide to Geotechnical Reliability Analysis for Stronger, Safer Foundations"

In construction, the ground beneath our structures often presents a challenge. Soft, unstable soil can compromise the integrity of buildings, roads, and coastal defenses. That's where deep mixing methods (DMM) come into play, transforming weak soil into a solid foundation. But how do we ensure these improved soils are truly reliable?

This is where geotechnical reliability analysis steps in. Think of it as a rigorous check-up for your soil, assessing its strength and stability against various failure scenarios. This method uses statistical data and engineering principles to determine the probability of structural failure, allowing engineers to design safer and more resilient structures.

This article dives into the world of geotechnical reliability analysis of structures using DMM. We'll explore how this approach is applied to real-world projects, what factors influence soil stability, and how engineers determine the magic number – the target reliability index – to ensure your ground is as solid as it needs to be.

Deep Mixing: The Secret to Stronger Foundations?

Skyscraper foundation reinforced with deep mixing method.

Deep Mixing Method (DMM) is a ground improvement technique that involves mechanically mixing the existing soil with cementitious materials, such as cement and/or lime. This process creates a soil-cement mixture that is stronger, less permeable, and more resistant to deformation than the original soil. DMM is used to improve soil for a variety of construction applications, including:

DMM is particularly useful in areas with soft, compressible soils, such as those found in coastal regions or reclaimed land. By creating a stronger and more stable foundation, DMM can prevent settlement, increase bearing capacity, and improve overall structural performance.

Foundations for buildings and other structures: DMM can create a solid base for buildings, bridges, and other infrastructure, preventing settlement and increasing stability.
Quay walls and breakwaters: In coastal construction, DMM is used to improve the stability of quay walls and breakwaters, protecting them from erosion and wave action.
Retaining walls: DMM can be used to create strong and stable retaining walls, preventing soil erosion and landslides.
Road embankments: DMM improves the stability of road embankments, reducing the risk of settlement and deformation.

However, DMM is not a one-size-fits-all solution. The effectiveness of DMM depends on various factors, including the type of soil, the type of mixing agent, and the mixing method. Therefore, it's crucial to conduct a thorough geotechnical investigation and reliability analysis to ensure the DMM design meets the specific requirements of the project.

The Future of Solid Ground: Reliability in Design

As construction demands grow and infrastructure projects become more complex, ensuring the reliability of our foundations is more critical than ever. Geotechnical reliability analysis, particularly in conjunction with deep mixing methods, offers a powerful approach to designing safer, more resilient structures. By understanding the factors that influence soil stability and applying rigorous analytical techniques, engineers can build with confidence, knowing that the ground beneath is truly solid.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1007/s12205-018-1136-x, Alternate LINK

Title: Reliability Assessment Of Geotechnical Structures On Soils Improved By Deep Mixing Method Ii: Reliability Analyses And Estimation Of Target Reliability Index

Subject: Civil and Structural Engineering

Journal: KSCE Journal of Civil Engineering

Publisher: Springer Science and Business Media LLC

Authors: Young-Seok Jo, Joon-Mo Park, Yeon-Soo Jang

Published: 2018-12-03

Everything You Need To Know

What is Deep Mixing Method (DMM), and how does it improve soil for construction?

Deep Mixing Method (DMM) is a ground improvement technique that involves mechanically mixing the existing soil with cementitious materials like cement and/or lime. This process transforms weak, unstable soil into a stronger, less permeable, and more resistant foundation. This is achieved by creating a soil-cement mixture. DMM is particularly beneficial in areas with soft, compressible soils, enabling the construction of stable structures such as buildings, quay walls, and breakwaters.

In what types of construction projects is Deep Mixing Method (DMM) typically used?

DMM is employed in a variety of construction projects to improve soil conditions. Common applications include foundations for buildings and other structures, providing a solid base to prevent settlement and increase stability. It's also crucial for coastal construction, used in quay walls and breakwaters to protect against erosion and wave action. Additionally, DMM is used in retaining walls to prevent soil erosion and landslides, and in road embankments to reduce the risk of settlement and deformation.

What is geotechnical reliability analysis, and why is it important when using Deep Mixing Method (DMM)?

Geotechnical reliability analysis is a rigorous method to assess the strength and stability of soil improved by Deep Mixing Method (DMM). It uses statistical data and engineering principles to determine the probability of structural failure. This analysis helps engineers design safer and more resilient structures by evaluating factors that influence soil stability. The analysis helps engineers to determine the target reliability index, ensuring that the ground is solid and meets the project's specific requirements. It's an essential step to ensure that DMM effectively improves the soil and that structures built on it are safe and durable.

What factors influence the effectiveness of Deep Mixing Method (DMM), and why is a geotechnical investigation necessary?

The effectiveness of Deep Mixing Method (DMM) depends on several factors. These include the type of soil present, the type of mixing agent used (such as cement or lime), and the specific mixing method applied. Because the success of DMM is contingent on the soil conditions and the chosen methods, a thorough geotechnical investigation is crucial. This investigation provides the necessary data for reliability analysis, ensuring that the DMM design is appropriate for the project's specific requirements and the soil's characteristics. This step guarantees the long-term stability and safety of the constructed structures.

How does the target reliability index relate to the overall safety and design of structures when using Deep Mixing Method (DMM) and geotechnical reliability analysis?

The target reliability index is a critical component determined through geotechnical reliability analysis when using Deep Mixing Method (DMM). This index represents a 'magic number' indicating the required level of safety for a structure. By applying rigorous analytical techniques and understanding factors that influence soil stability, engineers can determine the target reliability index. This index helps to ensure that the ground beneath a structure, improved by DMM, is sufficiently solid to withstand potential failure scenarios. A higher index corresponds to a lower probability of failure, resulting in safer and more resilient structures. The target reliability index guides the design process, ensuring a robust and dependable foundation.