During shield tunneling in highly abrasive formations such as sand–pebble strata, nonuniform wear of shield cutters is inevitable due to the different cutting distances. Frequent downtimes and cutter replacements have become major obstacles to long‐distance shield driving in sand–pebble strata. Based on the cutter wear characteristics in sand–pebble strata in Beijing, a design methodology for the cutterhead and cutters was established in this study to achieve uniform wear of all cutters by the principle of frictional wear. The applicability of the design method was verified through three‐dimensional simulations using the engineering discrete element method. The results show that uniform wear of all cutters on the cutterhead could be achieved by installing different numbers of cutters on each trajectory radius and designing a curved spoke with a certain arch height according to the shield diameter. Under the uniform wear scheme, the cutter wear coefficient is greatly reduced, and the largest shield driving distance is increased by approximately 47% over the engineering scheme. The research results indicate that the problem of nonuniform cutter wear in shield excavation could be overcome, thereby providing guiding significance for theoretical innovation and construction of long‐distance shield excavation in highly abrasive strata.

Based on the Yongdingmen Station of Beijing Metro, the underwater excavation method for deep foundation pit was introduced. This study constructed a numerical analysis model to analyze the performance of surface settlement and lateral wall deflection in the process of underwater excavation. Results showed that this method was better to control the surface settlement and lateral wall deflection compared with other dewatering excavations. In detail, most of the surface settlement was caused during the dry excavation stage and dewatering excavation stage while the deflection caused by underwater excavation only accounted for about 10% of the total settlement. Besides, the maximum settlement occurred 0.25∼0.5 H_e behind the retaining wall and the value was 0.04% H_e. Similar to the result of the surface settlement, most of the lateral wall deflection had been completed before the underwater excavation, which only caused about 7% of the total deflection. The maximum wall deflection and its location were approximately 0.06% H_e and 0.5 H_e, respectively. Moreover, a series of 3D numerical analyses were studied on the design parameters of the underwater excavation method. This study can be used as a reference for general performance and structural design of foundation pits with underwater excavation.

Cross walls have been used as alternative auxiliary measures to protect buildings in some areas of Asia. Realizing the inadequacy of the classical Winkler foundation to predict the deflection of the diaphragm wall with cross wall, a modified Winkler foundation of the finite element method (MEFB) was formulated in this paper. Then, the MEFB method was verified through two excavation cases and applied in a new well‐documented excavation history. Results showed that the wall deflection by the proposed method was line with the 3D numerical analysis and field observations but smaller than that of classical Winkler’s elastic foundation (EFB) method. The maximum deformation calculated by the MEFB method was predicted to have a reduction of 40∼60% compared to those of the EFB method. Meanwhile, the wall deformation was minimum at the location of cross walls and reaches the maximum value at the midline between two cross walls. Besides, the plane strain ratio (PSR_d) based on the MEFB method was defined to study the interval (L), the embedded depth, and arrangement of cross walls. The results indicated the MEFB method was used successfully as a more accurate method than Winkler foundation and is simpler than 3D numerical analysis method for the engineering design of the diaphragm‐cross wall system during excavation.