publish guidelines in a handbook titled Soil Mix Walls (publication pending). In this handbook, a methodology is proposed for the design of the soil mix walls for which the interaction between steel and soil mix can possibly be taken into account dependent upon the application. Ground Improvement The survey shows that ground improve- ment is gaining market share versus conventional piled foundations, and that will likely increase in the future. Enhancing the performance of the in-situ soil to make it constructible should be the preferred objective. The two major advances are the further developments on the concept of rigid inclusions and the recent advances in soil mixing as just discussed. The understanding that deformation and settlement are the real issues of foundation response has been significant in developing new answers to distributed loads in construction. The principle is based on mass soil reinforcement: creating a composite reinforced system by inserting inclusions in predetermined directions to improve the shear strength characteristics and bearing capacity of the soil. Rigid inclusions are usually installed using traditional piling or deep mixing techniques. Some more sophisticated tools have been developed such as Controlled Modulus Columns (CMC) or vibrated concrete columns. In these applications, the soil is preferably displaced and the strength of the material is adjusted based on design loads. and bending moments should not be neglected. The global design usually does include FEM analysis, as analytical methods prove to be too empirical. Testing and Monitoring The performance of deep foundations depends on local and equipment/crew- related parameters, therefore it is essential to properly document and verify the installation. Pile construction docu- mentation depends on the type of deep foundation being utilized. For example, driven pile installation can include the developments of electronic and hydraulic components of all kinds. It is possible today to instrument most deep foundation elements and to test their integrity, form and performance using the most advanced technology. The most common methods are Non-Destructive Testing (NDT) to evaluate structural integrity, Crosshole Sonic Logging (CSL) to evaluate the integrity of the concrete, and Thermal Integrity Profiling (TIP), which measures the heat of hydration along the shaft length to evaluate the entire cross section. There is no doubt that the generalized use of these controls improves the understanding of and exerts an important impact on the reliability of deep founda- tions, which should be taken into account in the analysis of the global safety of the system. Pile performance should also be controlled, if requested, using static, dynamic or statnamic load tests. Testing can be very important in detecting installation defects. Load testing is certainly one of the most Typical pattern and transfer platform for rigid inclusions automated recording of parameters such as driven length, number of hammer blows, hammer drop height and details of the pile section size. Dynamic monitoring can measure strain and acceleration. Docu- mentation should also include detailed annotation of any abnormality during execution, unexpected phenomenon, response of soil during installation (subsidence, uplift, lateral movement) or The understanding that deformation and settlement are the real issues of foundation response has been significant in developing new answers to distributed loads in construction. The design of rigid inclusions systems should include various components such as: global dimensions, internal capacity of the inclusions, enlarged head, design of the transfer layer, settlement and stability control, and plate bending moments (if applicable). The possibility of lateral forces obvious ways of controlling and assessing pile production and performance. A distinction should be made between load tests for design purposes and under- standing the general installation effect of pile systems. In this respect, the intro- duction of instrumented pile testing has enabled us to assess the load distribution along the pile and to have a better understanding of the separation between the end bearing and the shaft bearing capacity of piles. This type of test should certainly be generalized when introducing new or adapted systems. Installation factors should reward those piles whose effect on the surrounding soil has been tested and calibrated by instrumented pile load tests. Bidirectional tests (O-cell) can help the concreting (sudden loss of concrete, abnormal over-break) during the execution of bored piles. This information, if treated timely and with competent and trained engineers, can greatly increase the level of reliability of the deep foundation. Testing and monitoring has experienced major advances because of 86 • DEEP FOUNDATIONS • NOV/DEC 2015 practice by enabling load testing of highly- loaded large elements. The industry needs to work to continue development and acceptance combined with good instru- mentation. Dynamic load testing, on the other hand, has revolutionized the way pile production can be tested as a routine control and a statistical tool of pile performance control. When associated
